I don't even know why RC10's are so desireable, they were everywhere then and they're everywhere now, too. The only ones that command big dough are the new-builts, NIB, and rare special-edition offerings...no big surprise there. 5.0L Mustangs were a dime-a-dozen back then, from the late 70's to early 90's it was practically the same car. Are any of those truly collectible? Nope. A Taurus SHO or supercharged T-bird from the same era, much moreso.
Something that will become collectible in the future isn't always easy to predict, but rarity, pristine condition & originality/innovation usually play big roles. I can practically guarantee what WON'T be collectible: Anything that's a truggy. They're just way too commonplace. It would need to be something really odd and special-edition to be collectible 2 or 3 decades from now.
EDIT: I'd like to add that anything that survives several decades will become vintage. "Vintage" simply means anything old that's survived the ages. It doesn't always mean collectible or desireable. I always say "vintage crap is still crap".
