Generally, I'm quite pleased with the car overall. For 1996, this was a 'fleet only' vehicle, so the options package is a bit wierd (power locks, but no power windows. A/C & auto, but no cruise).
In late 1995, GM made a change in the 3.1 V6 engine which causes them to be noisy (most cars that had these motors in 95 & 96 experienced this issue). Lifter tap, piston slap, rod knocks, whatever you want to call it. I've been told this is caused by a leaky intake manifold gasket. After 50,000 miles, I have yet to address the issue and the engine runs fine. It does rob the motor of some if it's performance, but gas mileage is still the same (24C/31H). We've just renamed the car the "Gutlass" and keep on driving it.
The transmission makes a grinding sound when turning. The sound will dissipate once you're going straight. Almost sounds as if the tranny is running dry, but my fluid levels are fine. Could be a faulty transmission pump or lousy torque converter. I haven't bothered to address it and the tranny is still working. Another issue is hard shifting from 1st to 2nd, but that's only a sticky solenoid which will be fixed when/if it fails.
I have not had any issues with door handles falling off on any 90's vintage GM car I've owned... (all high mileage when sold/traded/junked)
These cars do rust, especially here in the Northeast! Trunk lids & gas tanks are always the first to go. Fuel & brake lines are usually not far behind.
Changing of rear plugs on any V6 is a pain. For these cars, simply removing the bracket for the MAP sensor will give better access. I actually did my own plugs without removing anything, took about 2 hours.
This was my second Ciera (the first an '87 w/V6), and has met my expectations. Keep the engines tuned up, and go easy on the tranny and these cars will last until they rot away.