One appliance and crew from Beaconsfield, one from High Wycombe and one from Gerrards Cross attended, along with an officer.
One car was well alight on the hard shoulder of the motorway when they arrived. The incident generated multiple calls to Thames Valley Fire Control Service.
The firefighters used one set of breathing apparatus and one hose reel.
Thames Valley Police closed the hard shoulder and lanes one and two of the motorway while the firefighters worked at the scene.
The car was destroyed by the fire.
The incident was left in the hand of National Highways.
