I think you're exactly right. An amusing comparison. I'm 6'3". My wife is about 5'6". Our legs are almost exactly the same length!

My problem in a BMW is that my head is crunched against the ceiling. If my torso is longer, that would explain why it is an issue for me but not for him.

The next problem that I get into is that leaning my seat back to get some head room won't work unless I scoot the seat forward so that my arms reach the steering wheel. At this point my knees wind up hitting the steering wheel. (Assuming that I could get enough lean/scoot to make it work at all.)

It is ironic that having proportionately shorter legs make knees hitting the steering wheel a big problem for me, but that's what happens.

I'm fine in Toyotas. (Though I wind up appreciating the fact that in California we scatter lights around so that there is almost always one that's fairly low that I can stare at. The traditional single light in the middle of the intersection is not in view unless I lean forward.) I'm fine in most mid-sized and bigger cars.

I'm emphatically not fine in my co-worker's BMW.

Cheers,
Ben