The rear seat is not designed for adults over 5 feet tall. Which means unless you have kids its just more storage space.
see full Audi TT review
What Our Members Are Saying about the Seat Room and Comfort of the 2006 Mercedes-Benz SLK
2006 Mercedes-Benz SLK Seat Room and Comfort: Pros
Year
Body/Powertrain
Comment
2005
2dr Hardtop conv.
Ample leg room and headroom - up to about 6ft 5 is fine
I'm 6ft3 and with the roof off I don't get too ruffled unless I go over about 85 mph
Lots of other things to like (and the running costs arent too horrendous) but I'm limiting myself to my top three
see full Mercedes-Benz SLK review