Fast Audis are theft targets these days, so I'd hold off on them for a bit.
A45 AMG....fell out of the ugly tree inside and out, but pretty damn quick! A mate has the latest 380hp version and it's definitely not a car I'd want to own. I preferred his old RS5 and R8.
Which leaves the 7R as a good choice, but again, it's on the ram raiders top 5.
Maybe some toning down parts from the lesser VAGs could be employed here. Stealth is always the best approach.