"When I was 17, I was living in and out of my '81 Oldsmobile Cutlass," T-Pain said on the episode, also featuring Common and "Twilight" star Alex Meraz.
"It was pretty beat-up on the outside and the inside, and it had a horrible smell," T-Pain's wife, Amber, added.
T-Pain's car put a roof over his head and provided a spot for romantic getaways. "I used to have sex in it a lot," he offered up bluntly.
During one steamy session, T-Pain and his girlfriend at the time were interrupted by intruders trying to break into the car. "It just so happened we were getting dressed," he recalled. "This guy tries to get into this car."
T-Pain wasn't worried; his car was filled with tools he could use to fight back.
"I got crazy amount of just things in my car," he said. "There's some pipes, there's a wrench. So I'm trying to pull my pants up and chuck this dude at the same time." The intruder eventually walked away.
T-Pain's girlfriend at the time was frantic and asked him a very ridiculous question. "My girlfriend was screaming. The stupidest question she asked me of that night was, 'Did you know that guy?' And I'm like, 'What? Why would I know this dude?' " T-Pain laughed.
"When I Was 17" — this week featuring T-Pain, Common and Alex Meraz — airs Saturday at 11 a.m. ET/PT on MTV.