Yobs poured acid over a parked car in Ferrybridge last night (Friday).
Firefighters were called to The Square at around 6.45pm after a Ford Cougar was found fuming in a lay-by.
Watch Commander Morris Blezzard said the incident near the Golden Lion pub was unusual.
He said: “The car was not on fire but it was fuming. Someone had broken into the front passenger side window and cut cables in the car before pouring acid inside the vehicle.
“It was a strange one for us. It’s the first time I’ve seen something like that around here.”
He said the owner of the vehicle has been contacted and it is thought a sat nav was stolen from inside the car.
Police confirmed the incident is being treated as criminal damage.
A spokesman said: “If anyone saw any suspicious behaviour in and around the car at the time of the incident, please contact Pontefract and Knottingley neighbourhood policing team on 101.”