At 10.01am on Saturday (1) one crew from St Neots was called to a fire on High Street in Yelling.
Firefighters arrived to find a car on fire in a ditch and extinguished it using a hose reel. They returned to their station by 11am.
The cause of the fire was deliberate. Anyone with information should contact police by visiting www.cambs.police.uk to submit an online report or call Crimestoppers on 0800 555111.