Actually I will support the faster after a wax job claim.
Let me give you scientifically based rationale. Fluid flow resistance increases with turbulence. Or turbulence increases the resistance and therefore reduces fluid flow rate. I will save you from a discussion on the theory.
Waxing a surface fills some of the imperfections. Those are scratches, craters, holes, etc. It also smooths the lumps and bumps by "leveling" the transition. By reducing the imperfections the air passes over the surface closer to a straight line. Straight line flow is called laminar. Each air molecule follows the one ahead of it on the same path which is the shortest (fastest) distance. Therefore the vehicle goes a bit faster.
Now let us address the situation when an air molecule meets a restriction that causes it to deviate from its linear path. Oops, it now deviates, yupster, to go over the barrier or into the hole. That causes it to slow down compared to molecules next to it as it now has further to go. And when it emerges from that hole it crashes into one coming on a straighter path or gets to the top of the barrier and effectively falls into a hole. See previous sentence to understand what may happen next. That my friends is turbulence.
Darn got some of that scientific stuff in here after all.
So lets save a bit of fuel and wax our old Chevys. No not drive faster as we might get an opportunity to visit a public official.
