Thanks for this. That’s interesting regarding the standard amp not being compatible with a sub as others have mentioned that it is compatible and just needs the wiring connect to the correct pins in the amp block. Does your screen software show the sub vol control in the Tone settings or do you use the separate sub amp vol controls to set the output and crossover of the sub. Thanks again 🙏The amp is under the passenger seat and you can get good access by moving the front passenger seat all the way forward. Unfortunately, the stock amp will not provide a subwoofer channel. You have two options:
1) Install a B&W amp, which will have the subwoofer channel. Apparently it's inconsistent on if you will get the sub control or not - there are other threads on this.
2) Tap into a speaker wire to run a separate amp. I went this route and tapped the rear speaker wires and added a small 2 channel amp to the trunk with the OEM B&W sub.
If given the choice to do it again, I would still choose this route unless I planned on replacing all of the stock speakers with B&W speakers (and even then I believe you will need to purchase additional wiring harnesses for the additional speaker locations you don't have).