Reposting what I wrote from a similar but more CN-specific thread on the Cartoon Network forum:
Total Drama Island/Action and 6Teen in "Canadian Wacky Races"
Setup: Chris, realizing the popularity (and money to be made/chance of seeing nasty wrecks) of NASCAR and similar auto-racing, convinces the network execs to sponsor a cross-country road rally featuring the stars of "Total Drama Island/Action." The network likes the idea, but wants some new characters to help liven things up (plus their marketing minions deciding that recruiting more than just teenagers would be worthwhile). One set of auditions at the Galleria Mall---and the construction/obtaining of a bunch of wacky race cars for the contestants---later, we've got the following contestants (fitting in the 6Teen/TDI cast members as closely to Wacky Races' format and drivers as possible---though given TDI has a bigger cast, probably more from there, sorry):
1. Jonesy in the Turbo Terrific: Lots of crowing about having the hottest race car on the track (and being "the hottest *guy* on the track")... until it falls apart, of course. (And yes, *somehow* he's also fired.... from *something*.... ;-) )
2. Owen and Mr. Coconut in the Buzzwagon: Owen's outdoormanship makes him a nice fit for this lumberjack-themed racecar, plus he'll get to take Mr. Coconut along for the ride. That and being afraid of planes makes the Crimson Haybailer a no-go...
3. Ron the Rent-a-Cop and Jude in the (Canadian) Army Surplus Special: Ron's pseudo-quasi-military mindset and Jude deciding to go along with the rent-a-cop for the chance to drive "a kickin' racing tank" makes for the perfect choice here.
4. Duncan, Courtney, Tyler, Noah, Wyatt, Jen, and Nikki in the Bulletproof Bomb: Duncan the juvenile delinquent is perfect for this 20s gangster-car, with Courtney as his "moll" and the rest as, well, his own "gang" of sorts (or someone for Duncan to intimidate... or at least *try* to, in Jen and Nikki's cases).
5. Darth in the Convert-a-Car: the only character out of this bunch (besides maybe Harold or Beth) with any grasp on science, or science-*fiction* as it were.
6. Caitlin and Lindsey in the Compact Pussycat: Yeah, I put two of them here instead of one---but given who they are (fashion-and-makeup-obsessed characters), guessing they'd love driving a "cute" pink-colored car with makeup-and-clothes-themed controls... and guessing they'd hit it off with each other.
7. Katie and Sadie in the Bouldermobile: They're practically twins already---plus like the Slag Brothers share the same brain. ;-)
8. Eva and Gwen in the Creepy Coupe: Eva's easily "Big Gruesome"... and goth-girl Gwen would probably love riding around in a haunted house-on-wheels.
9. LeShawna(?) in the Crimson Haybailer: Not sure for that one... thus I went with personal TDI favorite LeShawna.
10. Izzy and DJ in the Arkansa----er, Alberta Chuggabug: Izzy being, well, *Izzy* and DJ's cowardice at anything remotely dangerous should = one amusing racecar. ;-)
11. Heather and her sidekick, Stanley (the bratty six-year-old on "6Teen") in the Mean Machine: Yeah, Heather's the predictable choice as villain---plus Stanley makes for a good obnoxious little sidekick (who'll go along just to laugh at Heather as much as helping her pull stuff on the other racers).
As for the racecourse, I'll assume a cross-country rally from the Galleria Mall (apparently in Ontario, per one special) to far-off Sunset Island, British Columbia (yeah, a "Stoked" tie-in

)...
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If anyone asks, I could come up with one as a broader cross-studio "Wacky Races" crossover...
-B.