Profoxcg,if you can wait for the 1/10 IC On Road World Championship there will be your answer for what is the best car(my bets are 1st Pietsh (sp?)and S747 2nd,C02 or R4 one would win if no one else shows up),for the other questions:gear stripping on the Mugen since the MTX4 seems to be common but it's just proper building of gearbox,clutch and motor alignment,don't expect that pinions last forever.No problems with the tank and refueling.Oh,try the brakes with a spring instead of fuel tubing.