With the new crop of double-DIN navigation receivers being released early this year, I decided it was time to make the move to replace the Alpine IVA-NAV-10 in my Roadster 2.5. To say that I detested the Alpine would be an understatement as so much of it, in my view, was poorly designed. But other postings have berated the Alpine IVA-NAV-10 so I will not do so again here. I had three major improvements I sought with a replacement unit: (1) a real knob for volume control; (2) traffic information; and (3) speed sensitive volume. I managed to achieve the first two but not the third. In my view, having a lever like was on the Alpine on a radio for volume control is a an accident waiting to happen as it is difficult at best to find the control while driving. On the Roadster in particular, being able to raise and lower the radio’s volume is essential due to varying road noise at different speeds. I know that this means that the units with the largest screens are out, all of which forego a knob for volume in favor of a lever. But, for me, the volume knob was the most important. The two units I tried were the new JVC KW-NT500HDT, and the new Kenwood DNX-6990HD. Both units have all of the features of the Alpine including Bluetooth, HD Radio, Navigation and satellite radio. Unlike the Alpine, however, all of the features except for satellite radio are within the double-DIN unit and not add-on modules. Interestingly, the power draw of both the JVC and the Kenwood are substantially less than the Alpine even without all of the add-on units. The Alpine IVA-NAV-10 draws 4.35 milliamps with the ignition/unit off, and 2.18 amps with the unit on. The new JVC KW-NT500HDT draws 1.76 milliamps with the ignition/unit off, and 1.39 amps with the unit on. The new Kenwood draws 3.83 milliamps with the ignition/unit off, and 1.73 amps with the unit on. Thus, either the JVC or the Kenwood, even with the Bluetooth and HD radio modules built into the main unit, are substantially superior in power use as compared with the TESLA OEM Alpine. Neither the JVC nor the Kenwood appear to present power consumption issues in the Roadster. The initial install I did was the JVC KW-NT500HDT. Be forewarned. This unit will not be satisfactory in the Roadster because it requires a connection to the vehicle speed sensor. Even though the Tesla radio wiring harness connection has a wire for the vehicle speed sensor, for unknown reasons the JVC would not satisfactorily operate with the VSS. Rather, the JVC gave repeated VSS error messages. The JVC would satisfactorily read the VSS up to about five mph but thereafter give an error message. I went through JVC two firmware updates, and one change in the radio’s internal settings from “digital” to “analog” for the JVC VSS function, with the JVC techs who were amazingly helpful and responsive, in an effort to correct this issue. In the end, however, neither firmware update worked, and the change from digital to analog in the units’s internal settings did allow the speed sensor to work while the car was moving, but (somewhat humorously) showed speeds of approximately 500 mph while the Roadster was standing still, with the map jumping around like the car was flying. I finally gave up on the JVC after spending many hours trying to resolve this VSS issue. I should note, however, that even if the VSS had worked and not given the annoying error message every time the car started moving, I concluded that the JVC had too many other troublesome aspects to it that did not trouble me to leave it behind. The JVC lawyers have apparently gone overboard in making the new JVC unit a brick while driving. Rather than having a passenger adjust the radio, choose a song or work with the navigation, to use the unit it is necessary to pull to the shoulder of a road and run the risk of being mowed down. The grayed out screens in themselves should cause anyone looking at the JVC to think carefully about whether such a dumbed-down unit is desirable. I need to say a word of recommendation about the electronics dealer Crutchfield here. I purchased both navigation receivers from Crutchfield. After my experience with the JVC VSS issue, Crutchfield without any hesitation swapped that unit for the Kenwood DNX-6990HD. I could not have asked for better service or a more satisfactory experience from a retailer. I highly recommend Crutchfield for electronics as it is far better to purchase from a firm like Crutchfield that stands behind its products, than possibly save a few dollars. For the install of the new navigation receiver in the Roadster, the first choice is whether to remove all of the Alpine components including the two satellite radio modules, the Bluetooth module, and the HD radio modules. I opted to do so because I was looking to do this right. In retrospect, I probably could have left all of the extraneous modules in but that would be extra weight being hauled around and extra current being used. To remove all of the Alpine components, it is necessary to remove most of the front dash and the top of the dash. In a nutshell, start by removing the four small screws from beside and under the steering wheel. That releases the lower housing around the steering column. The molding around the radio pulls off. It is held there with four clips that will fall off and will need to be retrieved with a hook or other tool. The speedometer cowl is held on by clips and Velcro. The side panels (think of where the headlight control is and the like panel on the passenger side ) are held on with a combination of six screw and two clips each). Before taking off the side panels, take off the running boards which are held on by Velcro. The airbag panel has breakable plastic clips which will break. You should get four replacement plastic clips (get eight to be sure) from TESLA prior to starting the project. The top of the dash itself is held on by four screws. Here is a photo of the dash removed: You will need an Alpine radio removal tool unless the entire dash is being removed. It can be found on the web for less than $5. I am not sure if the removal tools that come with the Kenwood and other double-DIN units work with the Alpine but they may. The Alpine Bluetooth module is behind and to the left of the radio. In the well behind where the headlight switch are two Alpine satellite radio modules and an HD radio module. I never located the satellite radio antenna. I was told that it was probably behind the left headlamp. As it turns out, there is no need to replace it as, even though it was for Sirius and the Kenwood uses an XM tuner, the OEM satellite antenna works fine and has the same connector on it. In fact, in experimenting with placement of the antenna that came with the XM tuner, I concluded that wherever TESLA placed the satellite radio antenna works better for reception than just about any other location. The GPS antenna is not interchangeable between the Alpine and the Kenwood. I never found where TESLA put the OEM GPS antenna so I could not remove it, but I ended up putting the new GPS antenna under the speedometer cowl which works just fine. There is plenty of room under there for the GPS antenna like this. The Alpine back up camera will not work with any unit other than an Alpine as it is a proprietary camera that does not have a standard output. As the back-up camera for me was more of a distracting novelty rather than an essential element of the car’s system, I did not replace it. The USB cable in the Alpine unit is used for the HD radio module as well as for connections to USB devices which might be why the USB function appears to work so poorly on the Alpine. There is a USB cable with a male “A” USB connection on each end going from the Alpine navigation receiver to the HD radio module in the left well, and from there, a standard USB extension cable runs to the center console. I was able to use the existing USB extension cable to just reach the Kenwood but keep in mind that a new USB extension cable might be needed. Somewhere in the car TESLA put an amplifier for the speakers, and there is a subwoofer in the left rear wheel well. All of this works fine with the Kenwood. To wire up the Kenwood using the existing Alpine wiring harness, look at the diagram on the top of the Alpine navigation receiver itself after removal to identify the wires. The color coding on the TESLA harness is not Alpine standard color coding. Rather, the harness is an OEM TESLA harness made for the Alpine. I labeled each of the wires as I clipped them which is the prudent thing to do as once clipped, it is impossible to later match them up. The Kenwood has a wire for dimming screen illumination which the Alpine did not have. Such a wire is in the TESLA wiring harness but is not carried through to the connector for the Alpine. It is not essential to connect this up as the Kenwood can be set so that when the Garmin navigation system recognizes that nightfall has occurred, it dims the radio screen. Connecting up the illumination wire will dim the Kenwood screen anytime the headlights are on. Because I like to run the Roadster with the headlights on all of the time, I added a module with a photocell that senses when it is dark, and turns on power to a wire that runs to the Kenwood harness to dim the screen. To do this, I used a Directed Electronics 545T Nite-Lite System which is vast overkill for what I wanted it to do (turn on 12 volts when dark), but its $29 cost convinced me that I would spend almost as much in parts to design a circuit to satisfactorily do what this module was built to do which is turn on power when it is dark. The new Kenwood DNX-6990HD in my Roadster does everything the Alpine did, has the real volume knob, has a Garmin navigation system with traffic information which is far superior to the Alpine navigation system and allows for uploading of points of interest such as traffic enforcement cameras and charging stations. It does not have the speed sensitive volume although given the wide variation in Roadster ambient noise, I am not sure that if it did, it would be satisfactory. The Kenwood AM and FM radio itself appears to be somewhat less susceptible to the electrical noise generated by the TESLA. FM reception appears to be somewhat better, and AM stations with fairly strong signals are listenable which was not my experience with the Alpine. The one complaint I have is that the Kenwood screen in bright sunlight with the top down is not bright enough to be seen with polarized sunglasses on, even at its brightest setting, but I do not recall the Alpine being much better. The Garmin navigation system in the Kenwood is superb, and the Kenwood receiver has capabilities for Pandora, iHeart radio and the variety of other entertainment services being offered through smartphones. The Kenwood fits perfectly into the Roadster dash opening. Now, I need to list the Alpine on eBay.