Once you have found a car you like, (1) check that the person who sells it actually owns it, (2) check that no bank or loan company is listed ad having the car as security for a loan (online services exist for that, at least in AU), (3) check that it has not been registered as an insurance write-off in the past (also, online services for buying used cars often offer this check), (4) write a contract or use a standard form contract to ensure you have a document showing the date, odometer reading, names of parties, moneys paid... get signatures, (5) Importantly, ALWAYS get your own mechanical check done by an independent mechanic that you choose. Even if a car is sold with a safety certificate, you were not the customer of the mechanic who provided it and will have no recourse if anything goes wrong. Getting your own check will ensure that you are the person who pays for the service and who the mechanic has an obligation to. Again, here in AU, Auto Clubs offer mechanical checks for competitive prices. Don't be afraid to pay $150-250 for a mechanical check - it could save you thousands.