A security guard called the emergency services after spotting smoke and flames coming from the rear of a commercial property in the early hours of this morning.
The guard was on patrol near Water Lane in Exeter when he made the discovery at 1.25am.
It was found the flames were coming from a vehicle parked behind the building, which had been targeted by an arsonist.
Devon and Somerset Fire and Rescue Service sent one appliance from Danes Castle.
A spokesperson said: “We were on scene within minutes of the initial call and soon had the fire under control, after gaining entry to the premises using a ladder.
“One hose reel jet, breathing apparatus and a thermal imaging camera were used to extinguish the fire, which was started deliberately and totally destroyed the vehicle.
“Police were notified before the crew made the vehicle and scene safe.”