Go to your nearest dealer with your registration and have them order you a
master key for your vehicle. About $30.
Headrest problem is probably in the door switch. Unless you have taken one of
the memory switches apart before, DON'T.
Vibration at one speed and not another is a wheel/balance problem.
I have a 1989 560SEL and made it from Elmont to Saratoga in 2:45. Don't expect
more than 17MPG.
If you don't have any maintenance records, start with the 30,000 mile service as
a baseline for all your maintenance. One word of caution, if the ATF looks dirty
and smells burned, I would not recommend a full fluid service. Do the filter and
just the ATF in the pan (about 3 qts). Your fill point when cold is 1/4" below
the LOW mark on the stick.
If you have any more questions, give us a call at the shop.
Ask for Greg or Dick.
484 central Ave
Albany, NY 12206