So I'm looking at this 89 mustang as my next car since my oldsmobile finally went to that nice little junkyard in the sky. now I don't know the exact mileage all I can remember is the miles are low. I didn't get to drive it because it was blocked in by his mothers car and she wasn't at home. I was just wondering if there was anything that I should look for while I test drive it this saturday?

Also I have a transmission cooler that I was going to put into my oldsmobile can I still use it on the mustang? the mustang is manual.

Manual transmissions do not have oil coolers and there is no need nor any provision for installing one.

As for the car, it makes a big difference whether it's a V8 or 4cyl.
Obviously V8's are worth a lot more.

Check to make sure the top has no rips, tears, rot or damage. New convert tops are commonly available but pretty expensive.

Otherwise, the rest of the test drive is the usual stuff. one could write a book on the stuff to look for.
Look here for more info: http://www.samarins.com/check/simplecheck.html