Probably does seem a little overkill on a car but aerodynamics play a big role, esp at high speeds. Airlines spend countless hours washing aircraft, and thousands of dollars a couple times a year to have them waxed in order to cut fuel costs. Same with keep your windows rolled up(you may not be willing to drive with windows up and no A/C in your area, but it will help mileage), no roof rack, gigantic ass wings, tires that stick outside the body work, or wider tires at all (rolling resistance), it all adds up. Haven't you ever noticed how much slicker the surface of your car is after a fresh wax? The air sees the same thing, if your commuting on the freeway everyday it may help, but your mileage may vary.....literally"Keep car clean and wax it a few times a year." helps with gas milage how?