A passerby had informed Rewari Sadar police station this morning after which the body was recovered from the vehicle.
The deceased has been identified as Sunil, a resident of Arjun Nagar colony, police said adding that a country-made pistol was also recovered from the car.
The body has been sent for post-mortem and an inquest proceeded under Section 174 of the Criminal Procedure Code (CrPC), they said.
Meanwhile, the family member's of the deceased claimed that it was a case of murder, police said.