After a month (5 weeks) The regional rep finally called, to say that if the dealer techs couldn't replicate the problem, there was nothing to fix (no matter how many people we bring in to verify it occasionally slips, and no matter that the dealer has been in the guts of this trans 3 times). Plus, he was snotty about my writing to the dealer complaining that it had been over a month without hearing anything from the rep! But no worries, he said MB takes care of their customers, and would 'probably goodwill it if anything happened within a reasonable time frame'!
Also, the dealer service people who told me I should buy their Heritage service contract with 'wear and tear' and 'zero deductible' options to cover the trans after the factory warranty ran out, are now saying that the trans "would have to fall out of the car before the Heritage warranty would cover it"!
So today I dropped off another letter to the general Manager of the dealer, saying that if MBUSA wasn't going to replace the trans, then the dealer could repair it properly, or give me a letter saying that it would be fixed at their cost when it fails (as a supplement to the Heritage warranty), or they could refund the Heritage money and I would take the trans to another dealer, or we could get all formal and legal. I mentioned that this was a safety issue (I was nearly rear ended the last time the trans slipped while accelerating away from a light), and that I wasn't taking back the car until this was fixed.
To get things moving, I then went to the Credit Union which handles the MC card I used to buy the Heritage warranty, and put a hold on the payment for the Heritage service contract (The car has been in the dealer's possesion since before the contract was due to start, I haven't used it, and it apparently won't cover what they said it would do for my trans problem).
Any other suggestions would be appreciated - I haven't started picketing the dealership yet. So far MBUSA and the dealer aren't showing to very good advantage. Maybe Chrysler bought MB instead of the other way around.