The APR Oil Catch Can System traps excessive crankcase oil vapors and gunk from entering the engine. The system reduces carbon buildup on intake valves, and octane lowering oil vapors and oil pooling within the intake tract. It's a simple modification to install, drains in seconds with the flick of a knob, and is recommended at all stages of performance. Fits Audi A3 15-20, A3 Quattro 15-19, Q3 19-24, S3 15-20, TT Quattro 16-23, TTS Quattro 16-23; VW Golf 15-18, Golf Alltrack 17-19, Golf R 15-19, Golf SportWagen 15-19, GTI 15-20, Jetta 19-24