I'm not up on the current rules of the car, but I have a friend who 'helped' his son with some tricks, tricks that I haven't seen posted here yet.
BTW, they won every race (almost 20 years ago), and still have the trophies to show for it.
The trick is the wheel modifications (two mods to be exact).1)
Where the entire wheel sits flat on the track is drag not wanted.. they would bevel the car's tire ever so slightly so the ONLY point of contact of the tread was a small amount on the track.... slight 'V' shaped in the center of each of the treads2)
Only 3 tires would actually make contact on the track... One tire (I forget which one) would be elevated slightly... This will reduce drag.
The result was a very quick car and the envy of other scouts.
Futaba.. Always Imitated, Never Duplicated.