Hi Gary. These are very complicated topics for a forum such as this, and I'm trying to keep my answers short and perhaps oversimplified for Musiclover, who appears to be someone just getting started in audio.

I agree you're not going to hear everything even in the quietest of cars, and good for you that you have one. I did not mean to mix for a car, but to compare the sound in all the places you can listen, and go back and make small adjustments in the mix. What the OP should be looking for is a glaring mismatch in levels. You can't fix everything, though; bass solos, for example, are going to disappear in a car (mine, anyway) no matter what.

The best most of us can do is to learn how our monitors and our listening environment for mixing are not perfect, and we adapt. Let's all help the OP to get close without burying him in details that he/she will pick up in time. To that end, I will be guided by the level of the question from the OP.

You made a great point that you might as well put it all out there, warts and all, since hiding in the mix doesn't work. There's a funny message circulating now on Facebook to the effect that Jimi Hendrix remarked that people were copying his playing, even his mistakes. Gotta love it.

BIAB 2024 Win Audiophile. Software: Studio One 6.5 Pro, Swam horns, Acoustica-7, Notion 6; Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus Studio 192, Presonus Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors