cant really say much about your doors other then quit beating the crap out of them.
you could try popping out the dents and removing all the trim but i would suggest getting new doors and stop kicking them.
as for the fenders.
do you clean the wheel wells when you wash your car?
i use an old rag just for this area.
try cleaning the lip of the wheel well more often and i can bet that rust wouldn't be there.
too late now but if you ever get new fenders keep the lip clean and you should have no problem.
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http://www.cardomain.com/id/88ciera_sc
1988 Cutlass Ciera SC
3.8L Sequential Fuel Injection
Horsepower- 160 @ 4000 RPM<factory lie
Torque(lb-ft)-215 @ 2750 RPM
Displacement- 3802cc
4 Speed Automatic
This WAS My Dad's Oldsmobile