A farmer is awoken by noises outside and wakes up to see that a shadowy figure has just cut down his water tower and he knows that it's the work of the Raven.
Skip wants to teach Mudsy how to drive the Looney Duney and starts to give him driving lessons. Mudsy is doing well until everyone tells him what to do and he winds up crashing into a barn. the farmer, Mr. Higgins, comes in and thinks that the Raven sent them but they convince him otherwise. He tells him that he is about to lose his farm because of the Raven. Skip has an idea. They'll help the farmer by winning the cross country race that he saw a poster for on the way there. Unfortunately the Looney Duney is a wreck and they need spare parts to fix it. The farmer offers to let them use parts off his old steam tractor and Augie and Skip get to work combining the two. April and Mudsy come up with a name for the new car, the Monstermobile. The Raven's henchman sees what they are doing and he leaves to inform the Raven.
After they finish with the Monstermobile, the town banker, Otis Carter, arrives. Mudsy and Boo turn invisible so that he doesn't see them and Mr. Carter tells the farmer that he has an offer for his farm. Skip says that they are going to win the race and pay off the loan to the bank and Augie hops on the Monstermobile to show them and he proves that it is really fast. The Raven's henchman sees this from his hiding spot and knows that the Raven needs to know this too.
That night, the Monstermobile is stolen as everyone is sleeping but Elmo sees who took it and he and Boo lead the way to the old mill where the Raven is along with the car. They get inside and one by one, they are captured by the Raven until Mudsy and Boo are alone and scared. The Raven and his henchman has everyone tied up and they are put on a conveyor belt and start to move towards the grinding stones in the mill. Mudsy pulls the lever to stop it and appears before the henchman and scares him away. Mudsy then frees the others as Boo trips up the Raven. The gang then goes down a chute and find the Monstermobile. Unfortunately there is no exit but Mudsy uses the Monstermobile to create one and they get away as the Raven vows to stop them.
The day of the race arrives and Mr. Carter tells the gang that they don't stand a chance against his race car, the Formula One. The race starts and they start to take the lead. The Raven appears and puts out a detour sign and misdirects them and then takes it in before the other cars arrive. They go through some rough terrain and fall down a ravine where Mudsy is put in the driver's seat and everyone else is holding on to the steam pipe. They rejoin the rave and the Raven cuts down a tree to stop them but Boo takes the chainsaw from the Raven and cuts up the tree and they zoom past. the Raven then tries using a wrecking ball attached to a helicopter and attacks them. They are able to barely dodge the first two swips and go through a tunn and the ball catches on the tunnel and the helicopter is torn to pieces and the Raven parachutes out only to land in the Formula One and the parachute blinds the driver and they crash. The Monstermobile wins the race and the Raven is unmasked to reveal that he is actually Otis Carter. He had planned to buy the farm cheaply and get the land because of a rich ore deposit there.
Skip and Augie argue who is going to sit with April to the next stop and April tells them to both sit with her and let Mudsy drive. Mudsy takes the wheel and they hang on for dear life as he drives.