Both bimmer and MB can start/stop the engine if the

car is equipped with keyless access option. But you have to step on the break to use this push-button start/stop feature, which can be convenient because you do not have to take the key out of your pocket.

The 911 transcription indicated that the driver cannot operate the shifter or the breaks -- this Lexus must has 4 disc breaks and that should be able to slow down the car at least. Everything point to a computer lock down some sort.