I'm mapping my Audi S4 2.7TT at the moment, far far more complex than the aftermarket stuff - it's a real pleasure to do the likes of Omex now lol
Audi uses a Motronic torque and load based system with electronic throttle. There are thousands of maps and parameters, most interlinked with others - it really is an incredible system. I started looking into it in April and I am now at the stage where I can do pretty much anything with it.
The car was on an MRC tune which put out around 410bhp at 19psi, it's now doing the same power on 14psi and returning better MPG.
Rick