How about a little more info so we don't just fling remedies....otherwise
1. add oil
2. replace both fog lamps, they could both be shot.
3. I have a 95 E320 but I think the 98 may be the same, there is a dash board switch to turn the rear interior lights on/off
4. Brake job & tires are straight forward.

How many miles on the car?
Any history of maintenance (other than not keeping it clean)