Remember all that we might be able to find some components for elements of our design already on the market. As we do in FIRST, lets make this project worthy of the Creativity Award, reusing some common parts for uncommon purposes. A Jeep Cherokee 4x4 would probably work as an outer vehicle for our modified components and guidance system, which as M. Krass said, should probably be a combination of global and local (GPS and Radar, perhaps)..
Remember, PM me to confirm your team's interest in this competition, so i can get in the entry form soon. Thanks