unless you have a older model i dont believe the SR+ physically comes with the sub and extra speakers in a disabled state. heres a link to another thread with someone buying all the missing parts to upgrade to premium audio with a SR with part numbers in thread: Model 3 SR+ Premium Sound System Upgrade Video
I just bought the wire harness for the 2021 Model 3 SR+ from Hansshow. A buddy of mine has a 2020 SR+ and we were able to install it very easily last week. The only difference I see with the 2021 wire harness is two wires you need to manually plug in to each side of the front signal plugs. (Apparently no splicing of any sort needed)
I’m about to try and see if it’s feasible with limited instructions from the manufacturer. Haha...
Also, from 2020 SR+ and newer, there are pillar and mirror speakers installed, but not connected. There are no rear deck speakers or sub installed.
Just finished installing the Hansshow speaker activation kit for my 2021 Model 3 SR+ and everything went smoothly. I would recommend plugging everything in first before running your wires through the center console to test the audio first.
The only difference from the pre-2021 update is the missing front signal plugs (previously a more square shaped plug, and has been replaced by a red and black wire for each side of the vehicle. The instructions specify which wires to plug into. They share the same existing wire and for driver’s side, you match the black with black wire, and red with purple wire. For the passenger side, you just have to match the red with red wire, and black with white wire. Once everything was tested, I ran the wires under the carpet along the dip in the floor. There is enough of a gap beneath the carpet to not feel the wires through the carpet.
As expected, the front tweeters and mids were activated and produces audio that feels more immersive than the speakers closer to the windshield and in the door. The rear deck is missing speakers, although I connected the harness to it so the wiring was complete and neater. (No adverse effects as a result) I tested the left to right channels in the audio settings and everything was correctly functioning.
It was honestly very manageable! If you purchase the Hansshow kit, they supply a plastic pry tool that helps a lot with the panel removal. They also have instructional videos on YouTube for their pre-2021 kits. (The panel removal is the same, you just have to plug in those standalone wires on our 2021’s)
I kept the carpeting in place and lifted it up to slide the cables under the driver’s side floor carpet and haven’t noticed any bumps from doing so.
This install took about an hour, although I had helped a friend with his 2020 SR+ and I felt more confident pulling the panels off without breaking any clips. The best method is to go slow and take your time when removing any panel. I watched the instruction video at least three times before first attempting anything. The sound improvement is well worth the trouble though. It’s an odd feeling, as after a while, you get used to the better quality audio, but it definitely sounds much better.