Kirk,
Those look great! I built some pinewood derby cars with my kids for an Awana program at our church and had great fun doing it with them. Here's a sampling of ours...
Pantera?What does the shape/silhouette of this one remind you of? Definitely looks like one of our favorite cars. My son drew the shape on the block, I did the rough shaping - showed him how to use a chop saw, and he did the rest. Won 3rd place for speed.
1933 Bugatti Type 59This car won first place for style, but didn't make the finals for speed. My daughter did the final sanding and painting on this car.
1952 Ferrari 375 Indy This car took 2nd place for speed. This was my other daughter's car and she did the final sanding and painting too.
The "New Love Bug" My youngest daughter returned for a 2nd year of racing and wanted a "Love Bug." This car proved to be the FASTEST car at the races by a significant margin! True to it's 'Herbie' roots!
We glued up scrap pieces of a pine 2x4 on the top and sides of the derby block to get the shape she wanted, but didn't realize just how much more weight it would add. I ended up having to hog out most of the underside of the car to get the weight down within spec.
Definitely a LOT of fun. I helped my neighbor set up his son's pinewood derby car for Indian Guides - polished the axles, turned and smoothed the wheels, set the axles, etc. and he won 2nd place. Lots of fun for his whole troop!