Add one to the list - I am 6'3", 300 lbs. I fill roughly 30% of the interior space of my Targa, or so it feels. I went with a Momo Competition (I could barely feel that skinny three-spoke OEM), and I always move the seat as far back as it can go when entering and exiting.
I'll be doing a DE at Roebling this weekend, where that size keeps me from moving around!
Weight's a bit of a detriment though...
Me in the car: