Raj Singh's body was found at 6.30 a.m. in west Delhi's Shahbad dairy area, police said.
He was 45 year old and was working as a teacher in a Municipal Corporation of Delhi (MCD) primary school in west Delhi's Swaroop Nagar area.
A passerby spotted the car in the area and called up police, who found him lying dead on reaching the spot.
Police said his body was found in an Alto car and he was sitting on the driver's seat.
"The man was in an inebriated state and prima facie it looks like he suffered a heart attack triggered by excessive alcohol consumption," a police officer said.
The exact cause of the death can only be known after his post-mortem, but there was no foul play and the man had no external injuries, police said.