A new survey by website Trusted Dealers has found that two-thirds of people (65%) who buy second-hand vehicles from a relative find the deal more expensive in the long term.
The website, which questioned consumers who bought a car from a family member, found that 67% of the respondents were not happy with the deal.
Cost cutting is the reason cited by over two out of five (42%) people for finalising a deal with a relative.
The poll also found that 45% of respondents complained about mechanical problems, while 15% said their relative charged them a higher price for the vehicle.
More than a tenth (12%) said the vehicle had broken down.
Drivers might be better off looking for savings on their car insurance rather than using family members to track down their latest vehicle.
Neil Addley, managing director of Trusted Dealers, said: "The particularly alarming figure was the high percentage of cars that ended up costing buyers more than they expected in the long run."
© Press Association 2011