The condition of the interior is another important factor to consider when purchasing a used car. Excessive wear and tear on the interior may actually be a good indicator of a vehicle's mileage without even looking at the odometer. Additionally, dampness and musty odors, while not indicators of excess mileage, point to potential leaks in the weatherstripping, windshield or the vehicle's heater core. Foggy windows indicate excessive moisture inside the vehicle.

Indicators:

Brake pedal:  A brake pedal pad that has worn through to the metal beneath it is a good indication of a vehicle with excessive mileage. Think of all of the stop and go traffic it took to wear through the rubber, not to mention the wear on the braking system. If the odometer says 12,000 miles, RUN. 

Drivers Seat:  Take a close look at the drivers seat for another indication of excessive mileage. If the seat's outer edge has worn through, chances are the vehicle has quite a few miles... unless of course the driver was obese.

Floor mats and interior carpet: First, don't be fooled by a new set of floor mats. This is one of the cheapest and easiest ways to dress up a worn interior. While checking interior conditions don't be afraid to lift up the mats and feel the carpet to check for water leaks or look for wear on the right of the accelerator pedal and directly underneath. Remember the worn out brake pedal pad?  While sitting in the drivers seat, look at the windshield, taking note of pitting in the glass or stone chips.

Odometer & Instrument Panel:  Take a close look at the instrument panel to see if it has been tampered with. Indications that an odometer has been tampered with are fingerprints or scratches inside the plastic cover. If the mileage has been tampered with,  the numbers may not be aligned. The numbers should be aligned evenly accross. Look for scratch marks on the numbers which usually indicate a crude attempt at fixing the mileage.

Water Spots: In t-top cars and those equipped with sunroofs, water marks on the headliner are good indicators of a leak. To test it, grab the hose and hit it with a good spray. If it leaks, you can chew a few more dollars off the price to pay for the new seals. T-top seals run at least $100 per side, plus installation.