I think that a small town on a hill side would be cool. Tight turns overlapping, with a "downtown" and a "hillside" maybe a rock tunnel with a point in there. not huge skyscrapers but medium sized buildings. Multiple elevations for better sight since your in a vehicle and for unique traversing. many small "hops" or short cut-throughs. everything would have to be cut down though if budget will be a problem. If that is the case, using as much of the side of the large island is your best bet to reduce rocks at least. While if you create the map on the bacside of the large island, theres a "ramp" carved into the rock already, so that could be worked with. <--- Ideas