What do audiophiles do in their cars?

Yeah, I should of mentioned that my GMC is a 2008 in pristine condition. I drive my vehicles into the ground, so the cost of the gear is worth it in the long run.  Not to mention the JL Audio Amps were in my last vehicle as well, and I moved them over to this one - they have been kicking for 20 years now with no issues.....

only when the engine is not running, can i abide serious music listening in the car. when i am driving, i am a danger to other drivers if i am boppin' along to the tunes, so only news/talking head programs/audiobooks qualify for safe listening. i find almost all cars have mediocre sound insulation which also precludes serious  music listening. 

i think if i were one of the elect that could easily afford a luxury car with hushed interior and magic carpet ride quality, i'd just enjoy the hushed sonics as music of its own kind, i wouldn't wanna sully such a library quiet luxe with music or anything else. 

I listen to SiriusXM, CDs, FM in the AMG (Harmon/Kardon).  Best sound of my vehicles.

CDs and FM in the Z4M (Bose)...same as in the 97 Ford pickup truck.  Just replaced the truck's 4 speakers with Polk 6x9s, uses the original factory head unit am/fm/cassette with a 6 banger CD.

Just to keep it real...1976...had an am radio in a 69 Skylark, added the cursory (and terrible) FM tuner, 8 track player and rear deck speakers.  Accidently discovered the 8 track owner's manual last week... still have it after 45 years...don't ask me why; and looking back whoever thought 8 track was a good idea???  Sign of the times back then.

2018 Tundra Crewmax...Alpine head, Morel Ultra speakers (component in the front and coax in the rear), 2 AD 10" short throw subs in a custom box behind rear seats, Morel 4 channel amp for the speakers and mono amp for the subs. And then lots and lots of Dynamat extreme. 
I use my Samsung S21+ wired to the Alpine via USB C and running Andriod Auto. I play from Amazon Music HD to give the highest fidelity as the source. 
Basically, it gives fairly clean and clear music at most volumes I want to play it at. Even when I am not playing music, the sound dampening means the cabin is more quiet than most vehicles short of high end ones.