I have 2010 A4 2.0 and trying to make it faster without voiding warranty any ideas. I will be putting full exhaust but have no idea what a good brand exhaust. I was thinking borla?

 

The dogs for Audi exhaust are going to be AWE Tuning, APR Tuning, Stasis and Milltek. Personally I have an AWE Tuning exhaust on my 2013 S4 and LOVE it. It has a nice throaty sound, but it isn't obnoxious like a ricer. I run mine with the stock down pipes because I wanted a little more volume inside the car than what you get with the resonated down pipes and have been very happy with the set up. I'm going on a year running this set up. If warranty is a concern, Stasis will be your safe bet since Stasis matches Audi's factory warranty. They'll also be your choice for an ECU tune. FWIW, you'll see more performance gains from doing an engine tune (Stasis, GIAC, or APR) than you will from exhaust.