Car giant Vauxhall has recalled more than 500,000 vehicles after warnings that vital safety equipment could fail.
Owners of the Tigra and old-style Corsa models should visit their dealers so repairs can be carried out, says a spokesman.
Seat rails in the affected cars needed to be strengthened to prevent the front seats shooting forward in a sudden stop.
Nearly a fifth also need to have new seat belt buckles on the driver and front passenger seats, as they can come loose.
Both components may show signs of material fatigue and premature wear when under long-term, extreme load conditions.
In total, 586,538 cars need the seat rails reinforced and 116,000 of those also have problems with the buckles.
Vauxhall spokesman Michael Imeson said the firm's new Corsa models introduced last year were not affected by the recall.
"We have had no examples of either of these items failing in the UK, but we have had one or two in Europe. Nobody has been hurt," he said.
"Potentially the seat belt buckles could come loose and the seats could move forward without stopping."