Database marketing agency Eclipse is handling two safety recalls for Vauxhall and has been using the opportunity to collect the data through the prize draw.
After recalled vehicles are repaired at the dealership, mirror hangers are hung inside, thanking owners for their co-operation and giving them the opportunity to enter a prize draw.
Carl Taylor, account manager at Eclipse, said: "Since Eclipse is permitted to use DVLA data only in connection with safety recalls, the hangers were essential for capturing consumer data and obtaining marketing permissions."
Early difficulty arose when attempting to interpret consumer handwriting, but the problem was solved by changing registration from a paper form to a website Eclipse built.
Taylor said: "The online version of the campaign is going so well that Vauxhall have told us they would like to expand the microsite to support all future recall campaigns.
"By capturing user information on the back of recall campaigns, the manufacturer has been able to extend its reach beyond first owners, gaining information on a whole new sector of users."