I am replacing a clutch and flywheel now on my 2002 S4 now. It does that exactly. I press the acel and watch my rpms climb, while the car is just not responding.

 

a slipping clutch is different than jerking.. that is more like just no response.

 

Sent the s4 in on monday for the clutch job. I bought a rs4 clutch kit with al flywheel from awe and its friday now and still no car. THat sucks *** and I am really kinda pissed

 

there were only two times when my car did the same thing. one it was the TBB, but since you have the apr bipipe, we can rule that one out. second, the MAF. my maf hose slipped off once, and i had the same jerking and stuff. and then all of a sudden it just stalled. luckily i was just getting off the highway so i could pull over and see what the problem was. hos was off and it made sense. so good luck, hope it's not anything too serious.

 

I find this article very helpful about car jerking when slowing down. Read Here