I haven't figured out how to reproduce it...but mine had gotten so bad, it was BOUND to happen if they had it over the course of a day, and started it repeatedly.

I picked up the car today, and found that the interior creak was slightly worse, instead of fixed, so I went back. Took the actual technician with me for a ride, and got him honed in on the actual creak this time. He never found the source, but broke several interior panels looking for it, so replacements have been ordered. My rattled nerves need a rest from watching that. He said when the new interior panels arrive, he will pack foam behind them to get them nice and tight, and that may fix the creaking problem. Unfortunately, I suspect some welds have come lose and the whole body is flexing back and forth from the tiniest press of the gas, and release of the gas. This is in turn causing interior panels to rub together and creak. I'm not sure foam behind them is going to alleviate this, and it is ruining my experience of the car.

I guess now they'll call me when the interior panels that were broken arrive in, and have me come back down. For now, I have the creaking car, but it makes me sick to drive it.