I'm sure our other experts who've driven the 04 can tell better, but I noticed sitting in a GT1 at the dealers (didn't bother to test drive since the performance wouldn't be comparable to the GTP WS6 (almost) on order) that it seemed like less space between the steering wheel and the door. I adopt a very convoluted driving position with my left leg against the door and my left foot almost under the seat I also found the cruise control lever to be in the way a little bit (not sure what the point is of having it down at the 4:30 position).

BTW, I'm 6'0" and 270 but I lean back quite a ways in the seat (unlike you skinny guys) so I don't have a problem with headroom.