What do audiophiles do in their cars?

I have 3 vehicles and except for my Golf GTI which has a very nice stereo system i have upgraded the other 2 with Bluetooth players and decent but not extravagant speaker setups.  I predominately use Tidal playlists i have made up though on some of my longer trips 2500+km reception is not available, so I am sometimes reliant on saved MP3's on my phone, I carry around 50Gb of music for those times.  My ex Australian Army 4wd (Perentie Commander) is generally towing my semi off road van, so it works hard, so I have sound proofed it somewhat, floors and firewalls with double sheets of Roadkill, has a big turboed Isuzu truck engine under the bonnet which makes some serious noise so I have the speakers mounted in a false roof to blast away just behind my head or use noise cancelling headphones which cannot be used going thru towns and cities !!!  I need music to survive when driving long distances.

In my next car I want a better than stock hifi system, I don't understand why people don't order it everytime they buy a car.

So yes, my decision is influenced by this, I wouldn't buy one next time with basic sound system.

So, the correct answer is, "Whatever they want."

Sorry, you asked.

In my C-2, which is a DRIVER that I decided to buy after years of trailer-queens and a room full of dusty trophies, I put in a system against all the "rules."  The C-2 world is composed mostly of people who "listen" to their cars, and I get it.  I do too, sometimes. 

However, on a longer drive, I like some tunes, so I bought, before the major price increase, a look-alike radio from Antique Automobile Radio in Tampa (really Palm Harbor, but close enough for people who do not know the state.) Current price is $700; I got it for less a few years ago, and it is the same unit. 

Then, I was able to modify the Custom Auto Sound footwell speaker enclosures to fit my car, which has factory A/C (pretty rare--only 5% had it).  So, when my daughter is with me, she can blue tooth her music through the system, and I have a plan to do something along those lines as well.  

The daily driver (2007) needs a new radio--all of a sudden it is static-y when the engine is on.  I don't know what I will do there yet.

Cheers!

@richopp-    About your noise:

https://www.amazon.com/Car-Amplifier-Noise-Filters/b?ie=UTF8&node=10981591

Whatever they want , I used to have 6 amps and custom woofers,
in back and over 1500 watts , not to good have that much sound 
in a small area after I sold the car ,  we just have  the premium 
sound in the new Volvo X90 the Mrs says good enough .
this way I can save for a new set of speakers I am trying to max out around $20 k give or take . Ifyou can’t find something good for That price then something is seriously wrong.