My ml350 will start if it is cold but after running for a while it won't start. Mechanic tapped on computer and it started. This was after it had to be towed twice. Now dealer says there is a secret technical service bulletin. Parts in US(Jax) not usable. Must wait for new part from Germany - 10 to 14 days. Dealer also says several computers already replaced this year. Cost $3000. Anybody else having this problem?