Brake lines rusted through.
Radio only works when it feels like it.
Weatherstripping falling off.
This is my first car and I love it.
It handles great, and it's fast for its size. I have no trouble passing cars on the freeway.
It is huge and comfortable. It's great for driving all your friends around.
It's the best car I've ever drove. I wouldn't trade it for any new car because it's a true American masterpiece; I don't like Asian cars.
I had an '86 Caprice with almost 200,000 miles on it and it still ran great. I've heard of the police/taxi versions having had 300,000 - 500,000 (!) miles on them and still on the road! With regular maintenance these things run forever. I wish new cars these days were built to last like the 1980's Caprice was. Keep your transmission serviced, my sister had a '91 Caprice (newest body style before they quit making them) and had her tranny go out at less than 140,000 miles..
The '80s Caprices "cousins" were great cars too (same chassis, diff names) : Oldsmobile Delta 88 and 98 Regency (until '87 when they changed them to V6 FWD), and '80s Pontiac Parissiene. Hang onto it, it'll be a classic someday!
These eighties rear wheel drive cars are already becoming classics as we speak. The prices are very high for nice low mileage ones, if you can find them.