Haven't paid attention to the $parkfun autonomous vehicle competition, manely because the announcements come up so far ahead of time, it makes you feel aging faster than you really are. Was thinking about how a dead simple tricopter could win it, when I saw all VTOL was banned & there continued to be no altitude limit, despite rumors there would be.
Was going to say a dead simple quad copter with downward facing optical flow & sonar for stability & a gimbaled camera for position sensing could do it in the lowest altitude. It would scan blobs for the edge of the building & follow it around.
There's not much to a fixed wing solution besides going high enough to get GPS, having the best GPS available, having fully articulated control surfaces & enough power to do it as fast as possible.
There might be an advantage in a fixed wing specifically designed for speed, short flight time, & right turns. It would have a large vertical control surface, small wings, & a big motor.
Flying vehicles of any kind, in such a confined space, near all those cars, look too dangerous for them to continue. Even if they're allowed, it would be no fun to hit a car or a head.
A ground vehicle would still be amusing, if not winnable. A ground vehicle actually finished faster than the air vehicles. A competitive speed could be reached, with big enough wheels. A system using machine vision could be devised to plan a route ahead of time, then execute it using encoders.
The obstacles were placed in such a way that they could be avoided, merely by using a good enough GPS.
The dead simplest approach would be to manually drive around the building, recording all the distances & turns with encoders. Then play it back as fast as possible. The next step would be manually driving, with simple visual cues to aid the encoders.