Audi’s iconic TT is making a comeback and spy photographers captured the new model undergoing testing. What’s more, the TT RS will have 280kW on tap! Check out the third-generation TT!Despite its success, Audi never got around to a facelift for its current generation TT. Now our spy photographers have spotted what will become the third generation of the automaker's iconic coupe.2013 Audi TT (Spy) image galleryPORSCHE-RIVALLING TT RSA prototype spotted during testing at the Nurburgring, Germany, shows the evolutionary design of the new model. The next TT will be built on the VW group's MQB platform, shared with the seventh-generation Golf. From the side and rear it retains the design of the outgoing model but has a sharper front similar to that of the new A5 and R8. All TT engines will see a slight increase in power. The volume sellers will be the 130kW 1.8 and 163kW 2.0. A diesel will be part of the range, too, which musters 132kW.The TT S will use the S3’s 217kW turbocharged engine with all-wheel drive and a choice of six-speed manual or S-tronic transmission.The TT RS uses a 2.5 turbo engine boosted from 261kW in the outgoing model to 280kW.The new Audi TT is expected to make its debut in coupe form at the 2014 Geneva auto show, with the convertible variant likely to follow.