In my two years of this agony, I have never been stranded. I just pull over and restart. What I have noticed though is my problem is temperature related. The colder the mornings, the more times to restart.
On the 300CE there is a microswitch on the throttle linkage below the instrument cluster. We thought this was the answer, but it wasn't. There are definite linkage adjustments to be made on some cars. The brake pedal switch is a suspect along with anything in the brake circuit including the bulbs. The wheel speed sensors are fair game and make sure all 4 tires are the same make and diameter. I assume that your wiring harnesses are good.
If you DON"T get a warning light then you have the same problem as I have. We get only one fault and that is a "closed throttle idle switch"
Keep us posted please.
Anziani