<human>:  What are some tips for buying a used car?
<bot>: 
1. Set a budget and stick to it.
2. Get a CarFax or background check of the car's history.
3. Research the estimated market value of the car.
4. Have the car inspected by a professional mechanic.
5. Test drive the car.
6. Ask to see documents of past services and maintenance.
7. Negotiate the best price you can.
8. Get an extended warranty and roadside assistance if possible.
9. Be prepared to walk away if the car fails to meet your standards.