unfortunately like keeps being said we'll never going to get away from the "Toy Car" thing no matter how you dress it up!
take a final for instance from a spectator point of view-
the cars are small so its difficult to see them reacting to the terrain etc!
after a couple of laps you really can't tell who's in the lead
plus the race leader is even harder to predict in Nitro due to different pitstop strategies!
i suppose you'd need to focus almost as much on the characters driving to give a human element but as we all know RC isn't populated by a great number of "Rock star" types!
plus how appealing would a rostrum full of blue faced wooly hatted big scarfed large coated frozen gumbos look
bearing in mind we have at least 50% shit weather over here
even a wet meeting in the summer would look dreary!
i think the only way you'll have anything with any universal appeal HAS to be indoors, in a well lit, temporate environment. the track HAS to be spectacular with a long straight so people can appreciate the speed & plenty of big jumps for the OOOH AAAH reaction plus maybe incorporate something else a bit more interactive in another part of the building, maybe other side of pitting area, drifting or something else joe public might be attracted to? let em have a go! maybe even just a bank of linked up driving games?
(remember the 4 way Sega rally from years ago?) that might be popular?
you need trophy babes, decent announcer, the odd bit of loud music etc
some thing to add a bit of Razzmatazz
look at wrestling, its rubbish big sweaty blokes pretending to fight BUT people go mad for it as they Jazz it right up & put on a hell of a show!
you'd need to think of building some HYPE in to the event & more importantly into the run up to the event
then once you've got peoples attention they can just get used to watching the regular watered down stuff