It might appear that I'm attempting critical listening but I think my opening post was more a reaction to just how bad my car's stock system is. Literally I cannot listen to anything on it above a very quiet volume as certain upper mid frequencies are just so much louder than others. It really is unlistenable. I've had three cars in a row where the stereo was so bad it hurt my ears even at quiet volumes. So I guess I'm on a quest to see if my ears are hypersensitive, if the car environment is terrible for all manufacturers or if high fidelity is possible in the car world. So far it does appear that fidelity is possible.
I've been driving for years with music on and it never has taken away my focus from the primary objective which is safely driving the car. Indeed I'm known for being unable to have a conversation with on the road at times such is my level of concentration.
I'd argue that my current stereo is much more of a distraction than one that didn't shout down my ears.