The Plymouth Road Runner first appears in The Fast and the Furious: Tokyo Drift, driven by Dominic Toretto, who says "I won it from my friend Han a few years ago" when talking to Sean Boswell. This car featured a grey paint job and had black wheels.
Another 1970 Road Runner appears briefly as a protagonist car in Fast & Furious (2009), driven by Letty Ortiz. On this occasion the car was destroyed, being flipped over multiple times and then it was set alight by Fenix Calderon, who tells Dom "the last time I saw it, it was burning".
The car in Tokyo Drift is not the same as the one in Fast & Furious, since Letty's Road Runner is destroyed, which happens prior to the events of Tokyo Drift.
The car is seen again, as the flashback to how Letty died is completed. The car is shown being flipped over and Letty subsequently crawling out of the car. Fenix then shoots the car's fuel tank, causing it to ignite and the car to explode. At this point, the car is confirmed to be destroyed.
Dom goes to Tokyo to bring back Han's body so Han could have a proper funeral. While he's there, he finds out that Han had a protégé named Sean and decides to race him, bringing the series full circle to his cameo from Tokyo Drift. Dom then uses the Road Runner in a drift race against Sean. The Road Runner is then seen as Dom is sitting on the hood whilst talking to Sean about Han.
Another Road Runner is driven by Dom in Los Angeles (not the same one he raced against Sean in Tokyo) which he uses to drive to meet Letty at her grave site and attempted to destroyed her tombstone with a sledgehammer. He later drives it to Han's funeral. When Dom spots an Maserati at Han's funeral, he realizes that the driver is Deckard Shaw, and chases him in the Road Runner. They both end up playing a game of chicken; however, none of them move out of the way at the last second and both cars are damaged severely upon impact.