Thieves have stolen 29 sets of keys from a used car outlet in Cambridgeshire, leaving the business almost crippled.
Cromwell Car Sales in March is offering a £500 reward for information which leads to the keys' return.
The theft occurred last Tuesday at around 3pm while business owner Steve Smith took one car to be washed.
David Strachan, a friend of Smith, told the Cambs Times local newspaper: "Steve thinks he's finished. He cannot sell any of the cars without the keys and it will cost hundreds of pounds to replace them.
"We think the thieves will return at some point to steal the stereos. We don't think they will try to steal the cars because there are tall steel gates at the site."