I have the B6 S4, I've had it for a year and I absolutely love it. There are a few issues with the RS4 V8, it needs the inlets cleaning as they gum up due to the exhaust recycling system (FSI) they have for the emissions, but I'd have one in a heartbeat.

Here's Mine .;.....







Mine has a rebuilt top end with just over 5k since it's rebuild and was then fitted with numerous JHMotorsports (US Company) items including a level 2 map, taking into account the modified inlet manifold, decat and full milltek system. Sounds absolutely awesome. Also had all the suspension done, and it handles unbelievably. It had been in storage in a fully heated garage for two years after the timing chains started rattling which is a know issue on the S4 V8 and costs about 3k to fully replace the items that cause this issue with upgraded items. I bought it in this condition as the car was mint and did the work needed to get it back to 100% perfection.