I really like the retro look and feel with this logo! I love Entry #20 (Square) the best I guess, however the "Challenge" font from Entry #21 as well as the checkered flag are pretty amazing. Would it be possible to combine these two together?
One more thing. The trip is driven mainly by me, and perhaps one other driver - but this is unconfirmed. Can your try to use one motor / driver in the logo instead of 3?