Crews were called out to the blaze at Barnes Corner, Leegomery, on Thursday night. Nobody was hurt.
Shropshire Fire and Rescue Service said: "Fire Investigation called out confirmed deliberate ignition. If you have any information contact Telford Police on 101 or Crimestoppers on 0800555111 anonymously.
"At 10.11pm on Thursday, January 6, SFRS Fire Control received a call reporting a car fire in Barnes Corner, Leegomery.
"Small fire involving engine compartment of car. One hose-reel jet, small gear and thermal imaging camera used to extinguish fire and check for hot spots.
"One fire appliance was mobilised from Wellington."
West Mercia Police have been contacted for a comment.
It comes after a car fire outside the Whitehouse Hotel in Wellington on Sunday evening. Far-right activist Tommy Robinson claimed on social media that it was his car that was blown up in a petrol bomb attack.
On Thursday last week, crews dealt with car fires where flames spread from cars to buildings in Merlin Coppice and Thornton Park Lane. Both were being treated as arson but were not believed to be linked.
There was another fire two days earlier in Glendale area of Lawley Village. Fire investigators were looking into the cause of the blaze.