The Audi TT Roadster (MK3.5) is the open two-seat version of the base TT: same 2.0-liter turbo four, 7-speed S tronic and standard quattro, with a powered fabric soft top rather than a folding hardtop to keep weight and packaging in check. It trades the coupe's token rear seats and a little rigidity for open-air access to the drivetrain.

It drives with the same easy, all-weather character as the coupe. US availability was limited to the early part of the MK3.5 run before the American TT line narrowed toward the coupe.