Can't speak for you car, but mine had the same leak.
1) drain oil,
2) jack up the engine so as to be able to remove pan,
3) remove sender unit, which pulls out,
in order to replace two (2) o-rings. Now, no leaks.
Painful way but I HATE LEAKS! Probably should buy a Lexus! Maybe there's an easier way?
Regards . . . . JimF
'94 S500 Cpe
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