After watching my son get smoked I talked with some people and spent 30 min on his next car putting the wheels on. He won that year. Next year I did the same with both boys and they placed 3/4 and we're happy. Last year my kids searched online for tips on their own. Again I put about 30 minutes into setting the wheels and my son won.

I only actually set the wheels and nothing else.they cut the block. Sand it down. Paint it. Sand the axles smooth and do everything else.
I didn't care if they won but I sure did not want them to be last place and uncompetitive.