general problems of the 1999 Mercedes Benz ML320

I have 2 complaints against mercedes Ml320 SUV. 1) with ignition off and key removed, the transmission shifter can be shifted to neutral and the truck starts to roll. It posts extreme danger to passengers, especially, kids left in a parked vehicle, as well as pedestrians in front or behind the vehicle, especially those standing in between this vehicle and another parked vehicle on a slope. 2) the well known power lock failure causes the manually locked doors (including child proof rear door locks) to be unlocked automatically whenever the vehicle starts in motion from full stop. It is due to the auto-lock feature which attempts to lock all doors when the vehicle starts to move from full stop (e. G stopping for red light). However, due to power lock failure, it cannot lock all the doors after 4-5 times and eventually unlocks all doors. This left children in the rear in danger of opening the doors while the vehicle is in motion. This problem happened to me twice; one at 9700 miles in 2001 and at 70,000 miles in 2007. I had written a letter to Mercedes Benz USA to complaint about the power lock and they just denied that it is a defect.