Make sure the car hasn't been clocked. Look if the wear on the car looks greater than the mileage would suggest. The wear on the driver's pedals is a sign. Then look at wear on the tires. Check the wheel alignment of cars. Uneven wear and tear of tires-balding on the sides or in the middle-indicate poor alignment. Ensure that the paperwork is in order.
Visit the Registration Office before you sign on any dotted lines Things to check are
1) Registration Book (Registration Certificate Book) : RC book is issued by the RTO, showing date and address of registration and record of the owners of the vehicle. The car's Engine number and the Chassis number should be verified with that shown in the RC Book. If the car has met with an accident which involved changing the cars chassis, then the new chassis number would be recorded in RC Book
2) Taxation Book (Tax Certificate Book) : This shows the status of tax paid. The RTO tax is a once in a lifetime tax and should have been paid by the original owner of the car.
3) Insurance : Insist on the insurance papers, as these papers are mandatory for any transfer by the RTO.
4) Invoice : Do not forget to get the original invoice of the car from the original owner. You can know many details like engine no., chassis no., date of delivery, delivery dealer and whether the car was financed or not.