A passerby spotted the car on fire just before 5 a.m. ET near the intersection of Jean-Guyon and Michel-Bohec streets, according to Sûreté du Québec.
After firefighters put out the flames, they discovered the body in the vehicle, said Sgt. Benoit Richard.
Blainville police turned the investigation over to the Sûreté.
"Right now, we don't know the cause of death," Richard said. "We're not taking any chances and we're doing a complete investigation."
The area was closed off as investigators, including a canine unit, were brought to the scene to gather evidence.
Police haven't released further details about the body.