I finished changing all 3 speakers that are 4" in the front underneath windshield. These are the midrange speakers and after changing did notice some improvement. Gotta thanks to flashflooder and all the others that did before me. This guide includes a lot of notes from previous threads that I read. I hope this is another guide that can be helpful for anyone wanting to upgrade. Tool Needed: -Neiko 01325A Ultra Low Profile Offset Torx20 <Need this to remove screws of middle speakers -Infinity REF-4022cfx 105W 4" Reference Series x 3 -Short Feather Male Headers - 12-pin and 16-pin Need this to solder speaker wires to pin and from pin to model3 cable harness. -Soldering tool set needed , some extra speakers wires since the Infinity I brought didn't come with wires. Tutorial to remove grill and access speakers are already shown, search for thread Details / Specs on PUP audio system by @flashflooder Removing original speakers from harness: If you use a flat screw and push on bottom, it will unlock the original speakers from car harness, as shown in picture. Like other has mentioned, the wiring does not have any extra length that you can pull out and easily splice the wiring in so I used the method of soldering like other people here. Using the short male headers I solder into speaker wires and form this plug into the car harness female plug, shown in picture. In order for the speakers to sit more flush, I had to bent one side of the metal for screws, or else could hit the top grill. Easy to do with a pliers, see pic. I think I did this on the left and right speakers. I only used two screws to for infinity speakers and that's adequate after screwing tightly. Middle Speaker 1: this is where your special ultra low torx20 neiko comes in handy. With this you can remove the speaker. Middle Speaker part2: There's less depth here so after you remove the speaker, you need to reach inside a pull the clip that holds all the wires set. After doing this, you can push the wire set next to the side so it will ultimately create enough depth for the Infinity speaker to sit. See my blurry pic.