squeaks and thuds on a 300TE 4-matic

I have a 1991 Mercedes 300 TE 4-matic wagon with 93,000 miles on it. I bought the car with about 70,000 miles on it, and the car is a so-called "Starmark" car, which supposedly makes it the cream of the crop. The car was sold to me with one great used car warranty. Which is a good thing, as the car has been in the shop a little over *20* times in the 14 months I've owned it. I won't go into all the details; just 2 in particular. First is that the steering wheel has a persistent squeak to it. I've taken it back to the dealer at least 8 times and they have replaced parts 3 times and lubed something the other times. The repair never lasts more than a couple thousand miles. Usually less. They (Seattle MB dealer) have made many sincere efforts, but why can't they fix it?

The second problem is that after the car comes to a complete stop, after I take my foot off of the brake pedal, the car shudders and you can hear a low pitched thud accompanied by a jolt to the steering wheel. The dealer replaced the transfer case and the problem went away for about 1,500 miles, and by the time the car had traveled 3,000 miles the problem is back again. It is most pronounced when the car is on a hill (up or down doesn't seem to make a difference) The dealer now tells me that that's normal. Any insights?

…tracy