Cute title. A car only has one interior, right? Wrong. You need to check all of the car's interior cavities: the passenger compartment, the engine bay and the trunk. For simplicity, we will treat the area behind the rear seat as the trunk, regardless of whether the car you are looking at is a hatchback or notchback model. Failure to carefully examine even one of these areas could mean you have overlooked a potentially serious problem.

Start with the passenger Compartment.
The condition of the passenger compartment can vary widely, even on cars of similar age and mileage, depending on how conscientious and neat the previous owner was. Still, a thorough check could reveal some valuable clues about the car's history.

Look at the pedals, especially the brake pedal. These are your first clues to the real mileage. They should show normal wear. If they are new, odds are they've been replaced to hide high mileage. Beware. If the brake and/or clutch pedal have been replaced while the other pedals show normal wear, beware double.

Now look at the seats, really look at them. Are the seat covers original or slip-ons? If they are slip-on, try to lift them up to examine the originals. Are the seats themselves firm or do they sag where people would normally sit? Sags mean heavy use and weakened supports. Try to gauge if the seat wear corresponds with the mileage on the odometer. This could be another tip-off that the mileage has been rolled back.

Look at the carpeting. Lift up any floor mats and examine the carpet for wear. Again try to compare the visible wear to the mileage to see if it agrees. If you can, lift the carpet up and look for any signs of repair work or water damage (indicating a leak somewhere in the body). Look for welds running across the body, indicating the car is a "clip," meaning that it was formed from the good halves of two wrecked cars. You want to avoid those cars at all costs--they are generally structurally weakened and possibly unsafe.

Look carefully at the odometer for any scratches or misaligned numbers--clues that the mileage may have been altered. Though there are ways to alter an odometer without leaving evidence, most pros are in too big a hurry and will leave traces of their work. Also look at the Vehicle Identification Number (VIN) strip on the dashboard near the base of the lwft windshield pillar. It should be riveted on both sides, smooth, flat and recessed. Any evidence of tampering could mean the car is "hot," or stolen. The best thing to do if you find something to indicate the car is stolen is to walk away, no matter how good the deal seems to be.

Wiggle all of the handles and knobs. They should be unbroken and solidly attached. Lower all the windows, then raise them, then lower them half way. Wiggle each window; they should not move excessively. Pull each one up slightly to be sure that it is solidly mounted in the track. Fixing a window that is loose in its track isn't cheap. Try the sunroof if the car has one. Look in the recess around the sunroof for evidence of rust. Check the remote trunk and fuel door releases (if the car has them) for proper operation.

Test all of the locks to make sure they work. Open the glovebox and look for the owner's manual and maintenance record. Read through them quickly to see if the dates and numbers correspond to the current mileage reading. If either or both are missing, ask about them and try to get either the old ones or a new set to be supplied.

Now, move to the engine compartment.
Don't look at the engine this time, look at the actual compartment. The first thing to check is if the engine bay is the same color as the outside of the car. If it isn't, either the outside of the car or the engine compartment has been repainted. Even if they are the same color, there may be evidence of repainting, which can usually be detected by traces of overspray around the edges of the engine compartment, where the hood, fenders, and grille adjoin. Either way, someone has wanted to cover something up--maybe severe rust, maybe heavy body damage, or maybe just chipped or faded paint. Make a note for your expert determine the cause.

If the engine compartment has not been repainted, look for spots of rust, especially perforating (rusting clear through the sheet metal), either fresh or painted over. Look down past the engine and accessories to try to see the undercarriage. The pieces should be symmetrical from side to side. If any of the pieces look bent or twisted, make another note for your expert.

Now open the trunk.
Again, look for signs of repainting and overspray. Pull up the carpet or mat and look for evidence of standing water, either present or past (such as blistered paint or rust stains). Gently probe down into the fender wells on each side of the trunk, feeling for moisture, mud or rust. Any such material indicates that the car is rusting from the inside out and might not be a good investment.

Examine the spare tire. If it is a standard-size spare, does it match the tires mounted on the car? Does it show signs of abnormal wear, such as bald spots, cupping or excessive wear on one edge? These could be the result of front end problems that were covered up by replacing the other tires. If the spare is one of the compact, temporary kind, does it look like it's been on the ground for an extended time? If the temporary spare looks almost worn out, you may want to ask for a new one--those things aren't cheap.

While the spare is out, look in the wheel well for rust or repainting. Also, make sure all the parts of the jack and any tool kit are there. If not, you definitely want to insist that they be provided.

Now that you have completed your studies of the interiors, you're ready to move to the road test.