Raymond,

I had a very similar problem w/ my A1 GTI. I didn't have to hit a bump or anything, but after ~10 min, the car would start to break up at the top end. It would progressivly get worse to the point where the car wouldn't pull past 5k rpm w/o breaking up. I changed all the electrical stuff on the car (except the module, because I didn't think of it). New Bosch dizzy, new Bosch coil, new Bosch wires, new cap and rotor, but still the problem was there. On a whim, I swapped out the KJet box and the problem was gone! Makes me think it was something to do w/ the wiring in the module circuit (or at least related to the module circuit).