I have installed new cams, injectors, ECU chip, and installed in an e85 ethanol conversion kit into my 2006 Audi A3 and I am getting around 100+ horsepower in my car from the original 250hp.

There are a lot of little things you can do from exhaust, intake, but these barely add anything from the quality OEM performance that comes with the car.

I guess it just depends on how far you want to mod your engine...

 

Assadi,

Great looking car! Some of the ECM "flashes" are undetectable to the dealers. API has a system where you can change the setting to factory settings before bringing it in. Look into it if you're interested. I have a Tweaked A4 2.0T and my garmin has clocked it at 147mph.

Best,

Will