Retired swashbuckling actor Guy Roberts and his wife June are driving along in their vintage '59 Cadillac, playing movie trivia and discussing Hollywood history. They come to the town of Mesa and pull into a motel. They're unaware that MacGyver is in an upper floor, admiring the car and the couple. MacGyver is there to meet Tony Sullivan, a Syndicate member he knows from Afghanistan when Tony saved his life. Tony wants to meet with him to get protection. Two men drive up and go after Tony. Tony throws his satchel into the Cadillac and then runs for a wall. He tries to draw a gun but the two men gun him down and then drive away before MacGyver can stop them.
MacGyver calls Pete, who tells him to come home because the Feds are taking over. Meanwhile, the Roberts come out to find a drunk guest putting a bottle on the car. When the man refuses, Guy goes after him and breaks his cane. MacGyver separates them but when the man refuses to back down, MacGyver cowers and then offers to fight the man once MacGyver removes his jacket. He puts it on the ground and trips the man, then ushers him away. Guy is thrilled to meet him and says that they're heading to Hollywood so he can star in a new movie. They wish MacGyver well and depart.
The two killers, Tom and Phil, report to their boss Michael Talbot, who is staying at the same hotel as the Roberts. He isn't thrilled that they couldn't capture him. Talbot tells them to find the satchel: it has his money that he needs to give to his client.
Guy goes out to the Cadillac to put the top up and spots the satchel. He opens it and finds thousands of dollars in twenties. The next morning, the clerk discovers that Guy's credit cards are over the limit. Much to his wife's surprise, Guy pays in cash and leaves. Meanwhile, MacGyver is stuck on the road with a broken-down rental car. He tries to create a fuse out of a paper clip. At the hotel, Talbot, Tom, and Phil check out and notice new twenties in the cash register. They rough up the front desk clerk and learn that Guy paid with them, and that he's on his way to Hollywood in a Cadillac.
The Roberts are singing as they drive. Guy lies and claims that the studio paid him a bonus up front, and kept it from Anne as a surprise. She admits that she figured his claim that he had a new movie role was just a story he made up so he could take her on a trip. They spot MacGyver stranded on the road and offer him a lift. As they drive, Guy makes up a story about the movie he's starring in. Meanwhile, Talbot and his thugs are closing in and try to force the car over. Guy tries to out run them and Talbot draws a gun and tells them to pull over. MacGyver tells them not to pull over and then throws luggage at them. He grabs the satchel to throw but Guy stops him. MacGyver finally tosses back the canvas back cover, entangling the crooks' wheels. Next MacGyver cuts the convertible top loose and has Guy put it up when the pursuing car closes in. It flies back and Talbot and the others go off the road.
The Cadillac's engines goes out and they pull to a stop, with Talbot's car in sight a mile away. MacGyver discovers the fuel line is cracked and borrows Guy's autograph pen to bridge the leak. Meanwhile, Guy considers the satchel and starts to tell MacGyver what he did. However, MacGyver figures that the crooks are after him and admits he doesn't know what they're after. He then removes the muffler and crimps one end, then removes the knob from the steering wheel. Talbot and his men complete their repairs and MacGyver has Guy drive out. As they go, MacGyver cuts open the rear seat and uses the padding soaked in fuel to create a mortar using the steering wheel knob as a missile. He fires at the pursuing car and blasts open the radiator. Talbot and his men go off the road but the crooks refuse to give up the chase.
The Cadillac's oil light goes on and the car grinds to a halt. Guy reveals the money in the satchel and figures that's what Talbot is after. June realizes there's no job and Guy reluctantly explains what happened. When his wife wonders why he did it, Guy says he wanted to make her happy. An angry June doesn't believe it. MacGyver admits that he's probably responsible as well, and warns Talbot won't let the matter drop. They spot a deserted town nearby and MacGyver pushes the car downhill in neutral, leaving a trail of oil. Talbot is arguing with Tom and Phil when he spots the oil trail and figures they're close.
Once in town, the trio hide the Cadillac and pause for a breather. MacGyver realizes that the money is counterfeit and then has Guy remove the horn from the Cadillac. MacGyver then removes the battery and hooks up the car horn to the door of the building they're taking refuge in. June has lost her respect for Guy and the actor commiserates with MacGyver. MacGyver finally realizes Guy is talking about June, not the Cadillac, and makes a newspaper flower for the actor to give his wife.
Talbot and his men arrive and split up. Phil finds the Cadillac and closes in, and MacGyver slams him into the engine and then slams the lid on him. Meanwhile, Guy apologizes to June for everything he's put her through. She insists that she's stayed with him because she loves him. They're interrupted when Talbot finds them and takes them outside at gunpoint.
Tom spots MacGyver going into a building and goes after him. When he opens the door, he sets off the car horn and is deafened. MacGyver knocks him out and unloads his gun. Meanwhile, Talbot forces Guy to the Cadillac and demands the money. Guy rips off the radio antenna and duels with Talbot, disarming him and holding him off long enough for MacGyver to arrive and knock the criminal out with a thrown hubcap. June praises her hero and MacGyver finally remembers that he saw Guy in a movie, much to Guy's pleasure.
MacGyver drives June and Guy to Hollywood and the body shop where he and Pete have arranged to have the Cadillac restored to pristine condition. Talbot and his men have been put away and the counterfeit operation broken up. Guy notices one small scratch, but MacGyver points out it's a thread and blows it off the car.