Audis are understated, and probably in the US underated too. The S4 is a particularly cool car in my opinion. It looks to the casual observer like a regular A4, but packs some serious performance from it's V8 engine.
Compare with the BMW M3, that is clearly a motorsport tuned road car. Even my granny wouldn't confuse an M3 with a 330i.
The Audit TT is also cool, and is already a design classic.