So if I were to make a fondant road, going down a cake mountain, a matchbox car should be able to actually drive on it, right?

Anybody done this before?

It should drive on the fondant easily if the road isn't too sticky and is smooth... I made an 'over the hill cake' on the weekend and used a matchbox car on black fondant, I didn't want it to 'drive' but it would have been possible.
Perhaps a light dusting of cocoa powder/black colouring powder on the car wheels would help?

Good luck!

maybe if you applied a small amount of tylose or cmc to the road before you "lay" it? then it should dry a bit harder and be less likely to become sticky?

I agree with noahsmummy; some tylose or even just fondant that's been out for longer should work out. Cute idea!

To make the road look real, I saw an episode of cake boss where they covered the road in poppy seeds to make it look real...i just thought it was a cool idea! good luck