I'm pretty excited to have a German car to work on with Ethan. Recently Kelly's Dad upgraded to an RS 3, which meant his 2006 Audi A4 Quattro was for sale. Sounds like a good car for Kelly right? :) So the first upgrade that Ethan and I are looking at is the Engine Control Unit (ECU) This little upgrade has different modes for the octane of fuel that you are burning. This helps with the low end torque and with higher octane fuels it even increases the horsepower! Can't wait for the speed :).