Consumers are falling foul of "rip-off relatives" when it comes to buying second-hand cars, according to a survey.
As many as 67% of those who had bought a car from a relative had a bad experience, the poll by website Trusted Dealers found.
Also, 42% said they had bought from a family member to save money but more than 65% said the car had ended up costing them more in the long run.
The most common complaints after buying from relatives were mechanical problems (45%), being over-charged (15%) and breaking down (12%).
The survey also found that men were twice as likely to buy a car from their relatives as women, citing a desire to save money as the reason behind their decision. However more than 70% of men said they ended up paying more than they expected for their car.
Trust was the main reason women gave for buying from a family member, followed by saving money and convenience.
Being short-changed by fleecing families was found to be equally common for all age groups and not confined to young drivers buying their first car.
Based on responses from 2,000 motorists, the survey also showed car buyers in south-east England were the most likely to be ripped off by their relatives with more than 85% claiming they had been overcharged for their car.
Trusted Dealers managing director Neil Addley said: "This research is quite surprising and punctures the commonly held myth that buying from a relative will be cheaper and more convenient.
"The particularly alarming figure was the high percentage of cars that ended up costing buyers more than they expected in the long run."