I took a look at your map.. kinda looked ok until i realised i have done things in a very non standard way in the rcc mod. There are no object spawners as such.. the cars are attached to the 'buggy_spawn_support' object. this object basically spawns 'buggyred' which has 8 different random bodies for all the cars. you need to copy over all the objects folders for the cars and the buggy spawn support object.
But this it will get messy to do this and get it working properly..
buggy views are setup to show the welcome screen for rcc mod etc.
AND... before you go any further its worth pointing out that these cars DON'T drive on static objects like stunt pieces etc.. they will only drive on the heightmap.. anything else and they fall through. This is due to the setup i did in 3dmax to force the 'rcc feeling' to the cars.
you are in a world of pain with this im afraid.. but in all honesty if you can figure this one out you will learn A LOT about custom stuff and modding...
easier option is to take the one from streets_rcc instead... I think that one might even drive on stuff if you adjust the suspension when in game