Human: I'm looking to buy a used car but want to know how to avoid buying a lemon. Assistant: 
The best way to avoid buying a lemon is to do your research and make sure you get a vehicle that has been thoroughly inspected by a certified mechanic. You should also take the time to read reviews of the car before making a decision, as this will help you determine if it's a good quality vehicle or not. Finally, consider getting an extended warranty for added peace of mind.