The best mfg car stereo I had was an Infinity labeled system in a Chrysler Sebring. I believe what made it sound so good was the room - er, interior. A soft top lowered the noise from bouncing around, and when the rag top was down, the sound was even better. When one states that 50% of sound is the room, I believe it. So if sound is to be bettered in a car, you would need the engineer to start with a clean slate of nothing and work up from there.
I found the McIntosh in the Wagoneer to be a sellout of sorts; even the meters are merely screen shots. I do, however, believe that a far better McIntosh wireless bluetooth (or portable) system will be in the offing as Bose is really good with doing things "apple" like.
I wish I was on the other side of the pond! But the mfg claim could be said for the UK as well as they have yet to find peace with what has already happened.
I remind folks to give Leonard Cohen's edition of "The Future" (live version is the best) so that they can prepare to.."slide in all directions"..