Roadbuster, Leadfoot and Topspin, collectively known as the Wreckers, by Charlotte Mearing, had arrived with the second wave of Autobots aboard the Autobot ship, the Xantium, and were rarely let off of the NASA base because of their attitude. They would spend most of their time working on repairing their ship along with some human engineers, including Robert Epps.
When Sentinel Prime announced that the current occupation force of Autobots was to be exiled or the Earth would face the wrath of hundreds of Decepticons, the three prepared the ship for launch and accompanied Optimus Prime and the others aboard, sending the ship into the atmosphere - where it was then targeted and blown to smithereens by Starscream, seemingly killing all the Autobots aboard. Undaunted by this, the Autobot's human allies nonetheless tried to launch an incursion into Decepticon-held Chicago.
Fortunately for them, the Autobots were not actually aboard the ship, and had only feigned their deaths in order to keep the Decepticons from following up on their global threat. Leadfoot and the other Wreckers swung into action immediately, rescuing Epps, Sam Witwicky and a group of soldiers from a Decepticon fighter and executed the pilot. Upon being questioned on their apparent deaths, Roadbuster stated that they had built the ship, but hadn't been inside it when it had been destroyed.
While the Autobots were scouting a route to the building containing Sentinel's Space bridge pillars, Shockwave and his pet Driller separated Optimus from his weapons trailer. Optimus ordered Roadbuster and the other Wreckers to create a distraction so that he could retrieve it, and in their armored racecar forms fired at Shockwave with their machineguns until being forced to retreat, leaving behind Wheelie and Brains, who had hitched a ride with them. After Optimus had become snared in a construction site's cables, the Wreckers set out to free him. After doing so they rejoined the battle, battling against Devcon. After the battle Roadbuster stood with the other survivors, accepting that Cybertron was gone forever and that Earth was their new home.
Folllowing the Battle of Chicago, Cemetrey Wind began hunting down Transformers. Optimus ordered all Autobots into hiding, including Roadbuster.
It's confirmed that Roadbuster is still alive in Transformers: The Last Knight. You can barely see him playing volleyball with Topspin, but it lacks the body due to sunrise.