Yeah I think if I measure stuff more thoroughly I might stand more chance. Anyway, excited to try a low powered drive train to see if hundreds of watts of power really is needed. My beetle weight will happily push a 5kg weight around so am interested to see if pololu 37mm gear motors will shove 10kg. In which case its a cheap, off the shelf drive train. I have the battery, receiver and speedo waiting to go in so really should hurry up and order some motors and wheels. I like trying quirky and untested products. I was the only person running pololu wheels I think at the beetle champs and they were utterly spot on. Dunno why more people don't try some of the off the shelf stuff more often.