I met local car audio shop and explained the steps. They worked on Teslas but not on Model3 s. He agreed to most of the steps but didn’t see a need for LC7I or the 12v switched power source. Instead he is recommending a Class D amplifier 6 channel amplifier with GTO and LC builtin so it won’t draw power when the music is not on. AudioControl LC-6.1200 specifically. One other question he had was if the penthouse 12v power tap has constant power to the amp. Do you see any issue with this?