It's nearly impossible to guarantee that your pre-loved purchase isn't a lemon, but there are some steps you can take before handing over your cash to ensure that you know as much about the vehicle as possible. If you check any of the following boxes during your search into the systems and history of the car, you know it's time to walk away.
If the dealer won't show you proof of a professional license or of the vehicle's registration, move on. Licensed dealers pay into a compensation fund that you may have access to if the car purchase ends up in a monetary loss on your end.
Basically, if the car's true condition is difficult to determine on first visit and you're not welcome back for a second look during better visibility conditions, don't buy.
A certified vehicle must come with a safety certificate that has complete information and a vehicle identification number (VIN) that matches the car. The date of the safety certificate must not be more than 36 days old (including weekends and holidays), so make sure it's not going to run out before you have time to take the car home and drive it around in your daily life. A private sale care must come with a Used Vehicle Information Package—check that it has the seller's proper name on the package. The package will include information on any reason against licensing it, whether it has been written off or has any outstanding liens. The mileage will be recorded on there as well so you can make sure it matches the odometer.
Fresh undercoating has the uncanny ability to mask years of wear and tear that the previous owner would rather cover up than fix. If the undercoating looks too new for the year of the vehicle, you can't tell what's lurking beneath.
That's a sure sign of a collision, especially if you can detect areas of repair that don't match the vehicle's original color. Additionally, look for trim that looks newer than the rest, areas of paint overspray and ripples where the body wasn't properly prepared for the paint job.
That's any rapping, tapping or banging sound coming out of the engine when it's running, especially when it's cold. Check the tailpipe; the exhaust shouldn't be blue, black, or smell like antifreeze. Pull out the oil dipstick, and pass on the car if the oil looks creamy-white, which can indicate an internal coolant leak.
Familiarize yourself with the smell of antifreeze and use your nose to sniff for leaks under the hood. Do the same for fuel leaks near the tank and under the hood. If the car has been sitting for a couple of hours in one spot, move the car and see if it has left oil on the ground.
You can expect a clean, soapy smell if the interior was recently shampooed, but beware of heavy air freshener smells that could be masking cigarette smoke or mildew from water leaks.
If you can't take the vehicle for a drive, leave it alone.
Beware of the car that you have to buy right away, whether it's a private seller with a deadline such as moving away or selling it for a relative, or a dealer who says it's 'on special today'? or 'it will be gone tomorrow.' You can't expect to keep a seller waiting too long for your decision, but you should be able.