The episode starts in Rainbow Road and everyone have a race, but they mess up and Mario won by saying "Oh yeah, Mario number one!" After he runs over many people with his kart, he is ordered by The Judge to go to driving school. After thinking the teacher MCGustavo wants to rape him, he attends the class. But as Mario comes back to school, he messes with his teacher, causing the class to go insane. In computer room, Mario sees a princess and says "What's up?" and unknown princess answers "I'm a fucking pretty princess" and messes the room. He fails the test by giving wrong answers in computer due to his stupidity: Like thinking that: "What would you do if Lakitu's traffic light goes green?", he would drive into a pole and die, also driving over Peach during the 2nd question: "What's the main use for karts?" saying: "DIE, BITCH!" and says "boring" when it's extra question which says: "Do you take daily drugs and cigarettes?".
He tries to quit it, but as Mario chooses "I don't care:D" rather than "ok fine", Toad's head appears and says: "NO!" that causes it to explode. During the driver's test he crashes in a wall, then everyone laughs at him, then he asks them if they could do it better. Luigi goes first, ends up doing well, but slips on a banana peel, and launches himself halfway across the course. Peach starts to drive but then launches a spiny shell on herself, causing a nuclear explosion. Toad then tries, but when he gets a mushroom who he thinks that it is his friend Jerry, then loses his focus and crashes into a wall.
Waluigi starts, rips his clothes off, becoming Walurambo, then starts posing after jumping the ramp, and hits the sign. Wario tries, but it ends up by getting a star and having drugs caused him to fly away from track. Bowser has an awesome kart, which gets replaced for a small one, and it takes him two hours, but he takes a wrong turn and crashes in the wall. Then everyone has a race. To spare the details, Mario crushed Walurambo and won, Luigi got trapped by a ton of Ivo Robotniks, Peach's kart exploded, Bowser ended up on a sign, Wario shot himself into space, and Toad drove off to Racoon city. Mario got his driver's license in the end, and is excited when he won his license.
This is the first episode of Retarded64 to not include the name of Mario in its title. The second is Freddy's Spaghettiria (and it's the third if we doesn't count the fact that the episode "Mario and the 1337 P0lice" (which has been made between "Retard Karts 101 and "Freddy's Spaghettiria") is often called "The 1337 Police" only).
This is the third time Wario and Waluigi have had a major role in a Mario blooper, the first one was Race for Golden Overalls and the second was Mario at the Olympic Games. They originally come from SM64 series "The Wacky Wario Bros.".
Wario and Waluigi's models came from Mario Party 3, but when Waluigi took off his shirt and overalls to drive, a model from Garry's Mod is used.
Mario's license expires tomorrow (You don't believe me? It says it on the license!).
In the original Mario Kart saga, Bowser can fit in the kart, but in Smg4's version, he is so big that his foot is the same size of the seat of the kart.
Before the computer explodes, the song "Heut Ist Mein Tag" can be heard.
During the race, Wario and Toad use Toad & Wario's kart (well maybe Toad uses Baby Daisy's kart because he is too small), Waluigi uses Waluigi's kart, and Bowser uses Bowser's kart >_<(then again, Bowser wasn't supposed to fit in his kart, so it was probably Bowser Jr.'s because it matched and was small) while Mario, Peach and Luigi uses their own karts.
Wario and Waluigi are the only race participants whose failures (at the driving tests) didn't involve explosions (interestingly enough, Peach got blown up twice.)
While Mario was doing his kart, the driving instructor blew his whistle while punching. Strangely, his whistle is invisible.
Waluigi's emblem on his kart is surprisingly Birdo's.