Amongst the R/C boards, there's a lot of desire for stability at speed. These little cars can be juiced upwards of 70mph or more, and their short wheelbase and high center of gravity pretty much guarantee they go cartwheeling at the slightest twitch of steering. More often than not, the advice turns to adding weight to achieve stability.
As an illustration for why adding weight isn't the best idea, consider this: As far as the ground can tell, each of these vehicles weighs about 10,000 pounds. There's no argument which one handles better at high-speed.
For the big Ford, that ten-thousand pounds pure mass. For the Toyota MkIII prototype, only about 20% of that is actual vehicle weight.* The rest is from air pressure in the form of downforce adding road-hugging "weight" for grip without additional mass.
* Hiro Fujimori, designer, aerodynamicist Toyota Eagle MkIII. Mulsanne's Corner, 2002