Correct -- the headroom's not terrible w/o a helmet, but w/ a helmet for the track there's not enough room.
Apologies for not saying this earlier, but I have a Mk7 Golf R that I track and a new RS3 w/ sunroof that I would like to track. For me, it's the headliner around the sunroof that's too low with a helmet. You could argue that's too low w/o if you can hit your head on it driving around town spiritedly, but who's quibbling?
I measured the RS3 and the R this morning. Here's what I measured -- with the seat in it's lowest position, I measured from the rear base of the seat surface (where one's *** goes) where it meets the seatbacks as straight up to the headliner as I could eyeball. So from the *** crack of the seat to the lowest part of the roof--on the RS3 this was the headliner surrounding the sunroof, not the glass sunroof itself. For the Golf, it was just the headliner because it blissfully has no sunroof.
On the RS3, I measured 37" (which is 0.5" more than the published spec).
On the R I measured 39" (which is 0.6" more than it's published spec).
While the measurements differed from the specs for US models but 0.5-0.6", the delta of approx 2" matches.
So what I'm hoping to find out is if an RS3 with the solid roof measures closer to the R measurement -- does it pick back some of this 2" delta.
Thanks much for the help -- this is all adding up to if there's any reason to consider making my RS3 one of the first US FL sunroof deletes.