The win is the first for the agency since McCann Worldgroup acquired Meteorite in November last year and merged it with MRM.
MRM Meteorite won the account following a pitch, after a statutory review of the business was called in July last year.
The Vauxhall account was previously handled by MRM Meteorite's fellow Interpublic agency DraftFCB, which did not repitch for the business as the review coincided with its capture of Hyundai's DM account from Carlson.
DraftFCB's DM campaigns for Vauxhall include work for the Agila model in 2008.
McCann London was behind Vauxhall's recent advertising activity to support its sponsorship of the England football team, claiming it is "supporting a nation" with the deal.
MRM Meteorite declined to comment.