34-year-old Dunn appeared in all of the "Jackass" movies -- famously shoving a toy car into his rectum in the first flick back in 2002.
Dunn and an unidentified person both died in the crash which happened around 3 a.m. at Route 322 and New Street in West Goshen Township. It's unclear who was driving the car.
We're told the car caught fire in the crash -- and hours later, a tow truck was called to the scene to remove the charred wreckage.
Just hours before his death, Dunn posted a photo on Twitter showing himself drinking with friends.
Story developing ...