Just found this forum, LOVE Derby cars. My 8 yo and I just finished this, its his 3rd car. His first 2 were based off Hot Wheels, but this past summer he saw Speed Racer and got hooked. He told me in August that was what he wanted to make his car look like.
Our pack allows for a vehicle up to 2.75" wide so we added 1/2" balsa sides and cut this out on a band saw. Wheels are polished and trued, same for the axles. Current weight is 4.96 oz on my scale, the pack one seems to weigh a little heavy from my memory. Anyway, enjoy
Here's a symetry trick for you I learned as a kid in woodshop. Get you some 1/4" grid graph paper. Lay the uncut block on the paper and trace it, then find the centerline. You will need to do this as a top and a side view. Draw the pattern you want on half of the paper, fold it in half and cut it out. When you unfold it you will have even symetry and can lay it on the block to trace the edges for cuttting out.