I have the same knowledge of derby cars as my 6 year old son. So obviously we waited till 3 days before the race before even opening the pinewood derby box to see what we had to do then we found your video on YouTube. 3 nights later with my son doing the work that would leave him with all his fingers we got his 1st Derby car. Out of 4 races he finished 1,1,3,2. His was one of the faster cars there and we only polished the nails and placed the weight correctly. Next year we will follow all the steps and bring home a trophy. We had an amazing time doing this and look forward to the next race. Thanks for your video help.