[Drifter2]

@niklasw 
It seems like when the car is lifted from the track and put back on it is actually reseting the microcontroller in the c7005. It's possible the motor has a fault and is crashing the microcontroller with electrical noise. If this is the case then this motor will damage car decoders. 

A good test is to run just the motor on a bench power supply and measure how many amps it draws compared to another known good motor of it's type. Another test would be to run the motor in an analog car and see if it gets excessively hot with moderate speed. Also check the commutator for excessive wear if the motor has had a lot of use. 

If the motor checks out 'ok' ,  fitting a "ferrite man" to the motor may improve things.