When buying a used car, always check...

[$ilverbullet]

I'm about to buy a used car. I was wondering what should I always check besides the obvious mileage and exterior and interior defects?

[fatbot225]

Even though this post is a month old...

Go to

http://popularmechanics.com/

menu on the left. Put cursor on "AUTOMOTIVE"
then a sub menu appears.
Click on "Car Care" then a list of articles appear.
Go to archives or if it's listed on the page "Checking Out A Used Car"
"How To Shop For A Used Car", "Buying A Used Car" as well as other informative articles.

Here's a couple passages from "Checking Out A Used Car":

"Shady dealers will try to hide the defects rather than correct them. This is the man who uses that infamous recipe of pouring sawdust into standard transmissions to cover up noises caused by worn parts. Nowadays, heavy grease is used to mask the sound of worn gears and bearings. He'll "cure" a cracked engine block with a healthy dose of radiator stop leak--a temporary measure at best--and slap on a set of cheap tires to hide an alignment problem, or even worse, a bent chassis."

"Your inspection should take a double approach. You are looking for evidence of serious damage, which should immediately disqualify the car, and minor or cosmetic deficiencies which you may be able to use as a lever when negotiating price. Signs that a car has been detailed or reconditioned should not be the sole grounds for disqualifying a car. But they should be noted for later, more intensive checking by you or your mechanic as to the car's actual state of health."