Mr. Turner is having his midlife crisis, so he goes with Timmy to buy toys to help him feel young. He spends both of their toy money on a Striker Z, a car he always wanted, sold to him by Vicky (who admits it really wasn't hers). Timmy, upset that his dad is spending more time with his new car than with him, wishes himself merged with the car. Unfortunately, when Vicky learns from Doug Dimmadome that the car is worth a lot more than what she sold it for, she steals the Striker Z with Timmy still merged with it!
It is Saturday, and Timmy wants to play baseball with his dad, but his father keeps putting him off instead for chores such as mowing the lawn, painting the house, and digging for the underground city of Mole People. When all of his father's chores are finally checked off, Timmy excitedly asks his father if they can play catch now, but his father is upset that he looked in the mirror and saw he had a gray hair in his nose, the tell tale sign of old age. Wanda notices that Timmy's father is going through Mid-life Crisis. Cosmo thinks this is a good thing and wants to go through one, and starts to pursue his dream of water color painting. Cosmo does not have much luck at this since he, as a goldfish, he is already in water and the paint just fills the bowl instead.
Timmy's dad asks him what Timmy does to make him feel young, and Timmy answers "Buy me toys". Timmy's dad is driving his son to the toy store so that he can buy a radio controlled Striker Z, something Mr. Turner has wanted since he was a kid. Timmy points out a real Striker Z on the side of the road, although it is old and beaten up, Mr. Turner is thrilled and wants to buy it from Vicky who doesn't even own the car, yet still "sells" it to him for fifty bucks, as well as Timmy's fifty bucks, for a hundred dollars total. Timmy's father eagerly starts up his dream car and drives off, leaving Timmy in the dust. While Timmy chases after his father, Doug Dimmadome approaches Vicky and wants to buy that "antiqued metal death trap" for his Dimmadome Auto Show. Vicky says he is too late, but Doug Dimmadome offers to pay ten thousand "dimmadollars". A slot machine then reveals the word "Jackpot" in Vicky's eyes, and she tells Doug he isn't too late after all. Doug tells her to deliver it to his Precariously Perched Cliff-side Estate. Vicky vows to get the car back.
Timmy asks his father if he wants to play baseball now, but Mr. Turner is too busy fixing up his "new son- I mean- car". Timmy asks his godparents if his father is going crazy about the car. Just a few seconds of watching him shine, polish, and floss the car answers their question, "yes". When the car is fixed up, Timmy asks his dad if they can go for a ride, but Mr. Turner just wants to be alone with the car, and he quickly backs out of the drive way, running over Timmy's baseball and leaving him behind.
A week later, Timmy asks his father if he wants to do something together, but Mr. Turner has been with his new car all week. He even brought it into the kitchen with him when he was reading the morning news paper. Mr. Turner wants to go to the Dimmsdale Auto Show, Timmy asks if he can go too but his father says no, only people who are old enough to drive in can come. Vicky overhears this too, and realizes she can get even more money now that the car is fixed up. Timmy is getting upset that his father cares more about the car than about him, so he decides he will spend time with his father if he likes it or not. Timmy wishes himself into the Striker Z, and he becomes the car. Timmy and his father go through a ride through town. His father nearly gets into an accident, so Timmy takes control of the car. They arrive at the Dimmsdale Auto Show, where Mr. Turner shows off the genius car that talks and drives itself. Unfortunately for him it does not have a bathroom, so Mr. Turner runs off to find one. Vicky sneaks in and steals the Striker Z. While Vicky speeds past Mr. Turner in his car, Timmy pleads for help, making Mr. Turner think that his son is stowed away in the trunk. He gives chase, running into a car's engine and getting chewed up by the air intake.
Vicky calls Doug Dimmadome and tells him to get her cash ready. Timmy cries to Cosmo and Wanda for help, but Vicky recognizes his voice as one that she hates, so she changes the radio dial to a Spanish language station. Timmy starts to speak in Spanish and Cosmo and Wanda can no longer understand him. Mr. Turner borrows a kids scooter and chases the car down the road. A car chase ensues between Vicky in the Timmy-Striker Z and Mr. Turner on the scooter. Just as Mr. Turner is getting close, the battery on his scooter dies, so he rips off the handle bars and starts using the scooter as a skateboard. Vicky is closing in on the Dimmadome Estate, but Mr. Turner is catching up to her. She speeds all the way up the winding mountain and reaches the Estate, nearly going over the cliff in the process. She hops out of the car and Doug Dimmadome approaches her with a suitcase of money. Mr. Turner arrives and Vicky starts to apologize for "stealing her stolen car back", but Mr. Turner wants none of it. The extreme chase he put on "shredded his way through Mid-life Crisis" and he is only concerned about Timmy in the trunk. Cosmo and Wanda change the radio dial back to English, and Timmy wishes himself back to normal. Timmy appears in the trunk just as his father opens it.
Timmy is upset at his father because he ignored him in favor of the car, not even letting him ride inside, but Mr. Turner explains that the car is a "screaming metal death trap" with no air bags and pointed jagged edges, and that he would never let his son ride in a dangerous vehicle. Vicky buys the car back from Mr. Turner, and he runs off with his son to go play catch. Vicky then asks for the ten thousand dollars from Doug Dimmadome, but before she can get her money, a fly lands on the car which is still perched over the side of the cliff. The car falls and plunges into the rocky waters below, with Cosmo and Wanda still inside. The smashed up car lands on a whale, who launches it from its blow hole into the junkyard, where the car is promptly crushed into a cube. Cosmo enjoyed the ride saying "Let's go again! Let's go again!" even though it was a screaming metal death trap. Doug Dimmadome tells Vicky the deal is done, so Vicky replies with "Dimma-drat!". Timmy and his father are playing a game of catch while Cosmo and Wanda look on. Cosmo is going through his "escape artist phase" now, and is tied up in a tank with water slowly filling up. Wanda poofs away, leaving Cosmo to rescue himself out of the water tank.