Audi's range-topping, Porsche-fighting TT-RS, expected to debut some time in 2009, has been spied yet again in undisguised testing.

The latest spy shots of the eagerly-awaited Audi TT-RS have surfaced, and the upgraded coupe looks more than ready to go after rivals like Porsche’s Cayman and BMW’s Z4 M Coupe. The range-topping TT-RS is expected to go on sale some time in mid-2009, and rumor has it that Audi’s new 3.0 liter V6 will be under the hood, featuring a supercharger and 340-350 horsepower.

What isn’t up for speculation is the aggressive look of the TT-RS, whose massive air intakes and new front spoiler are evident in these photos. The suspension seems to be lowered as well. Audi’s signature RS oval exhaust outlets are visible, as are larger wheels wrapped around larger brakes. The prototype in these photos appears to have ceramic composite brakes, but there’s no word as to if they’ll be standard or optional on the production car.

Audi TT-RS Teases Us Again