[EricH]

For many of the elite teams, I'd have to say continuous improvement.

Find something about your team every year to improve--sponsors, facilities, members, funding, whatever. Every build/competition season, do the same for your robot (multiple competitions help, but you could probably get a similar effect by stealing ideas from competitions before your own).

Oh, and one thing you should probably be able to do, at least after a couple years of improvement: build a second robot. Between ship day and competition, drive the wheels off that second robot. This will give both a testbed for stolen ideas and a lot of driver practice.