Hello,

I recently purchased a 1985 BMW 318i - 146,000 miles. $1100 very little rust. It runs well (so far).

First the good  - I know that the following things have been replaced:
New tires
new brake pads front and rear
new front brake rotors
new ignition wires, plugs, distributor cap
new oxygen sensor
new drive shaft guibos (BMW's verison of U-Joints)
new shift lever bushings
new front suspension bushings
new rear shocks and bushings
new clutch slave cylinder
rebuild front brake calipers
replaced the exhaust manifold
replaced the turn signal switch

THE BAD -  My mechanic examined the vehicle over the weekend and discovered that:
- The driver belts are touching each other because the power steering mount bushings are bad.
- He suspects that the transmission is bad
- The windshield wipers do not work.
- All of the suspension bushings are cracked.
- The transmission leaks.
- There are multiple oil leaks.

I need advice. How long would you estimate that this car can be driven if I make short drives (less than 10 miles)
How much can I sell it for, knowing all that is wrong with it?

Any other advice would be greatly appreciated.

If you don't do all or most of your own mechanical work...dump this car right now

If you can and will be doing your own work then there may be a perfectly good car under all these problems. I wouldn't drive the car in it's current condition...at the very least, fix the wipers and the alternator mounts. You didn't say what was wrong with the transmission or if it is auto/manual but if it changes gears and drives the car, it should be good enough until you can replace whatever is worn or the tranny itself.

If you aren't mechanically inclined, this isn't the car for you 
Sell it off and if you're lucky you might get most of your money out of it but I kind of doubt that.