Still looking at an A4, and probably a 2007/08 2.0 170 TDi.

Despite what the wife thinks I will be remapping, preferably with DPF delete, lowering and adding an exhaust- of course, unless there are known problems with any of that?

*Is the 170 available as a CR engine, and if so what year was it introduced?
*Is the PD a better option for tuning, either in terms of reliability or results?
*Does quattro affect remapping at all - or, perhaps more importantly, does remapping affect quattro in any way?