Here are some tips on how you can buy a have a quality used car, so as you would not be replacing unnecessary parts along the way...Hope, this might help...
Tips & Warning
• As a final precaution, take the car to a mechanic, who should charge a reasonable fee to check over a used car. The seller should agree to this, but may require that you leave a deposit. If the seller won't let you take the car, offer to meet him or her at a mutually convenient garage.
• If you give the seller a deposit in order to take the car to have it checked, make sure to write out an agreement stating that the deposit will be returned immediately if you decide not to buy the car.
If the vehicle's mileage appears unusually low, have a mechanic determine whether someone has tampered with the odometer. If so, the seller must refund any money you have paid and may be liable for punitive damages under federal and state odometer laws…
This is how I acquire my car; I inspected all its auto parts from exterior and interior aspect down to its Saab catalytic converter and other accessories. By doing so, you could be sure of the quality of vehicle you are getting.