* How long do the hydraulic suspension spheres in the back typically last?

If the roads you usually drive are well paved they should last about six to eight years. If not, they usually last from 3 to 5 years.

* The accelerator seems both harder and less smooth / linear than on my 300SE: normal?

All M.B. accelerators are hard and unsmooth.

* * The radio gets surprisingly hot after driving for a few hours: is this normal on this model?

Some radios do get unsually hot, sometimes they even fry themselves. It used to be pretty bad when Mercedes used Beckers. The new Panasonics (which is the one your car must have if it is the original, are much cooler).

* I only have sound from the front loudspeakers, even after trying to adjust the radio's "fader": is there e.g. another button somewhere?

There is a well known design flaw on the 124 T, the cables that enter both rear doors (and this will answer your next question) tend to get splashed by the B-pillar interior cover (which runs from the ceiling down to the floor). This will eventually render your rear speaker and rear door lights inoperable.

You must find where the cables were cut and fix them. Usually the when the cables get cut, a fuse inside the radio will blow out, so be prepared also to take out the radio and change this fuse before the rear speakers become operable again.



* The lights under the rear doors don't come on when the doors are open: same question.

Thanks in advance![/QUOTE]

__________________
A. Rosich
CL 500, 1998
S 500 L, 1998
E 320 T, 1995 [Sadly sold ]