There is a very good reason race cars have rear wings, aka spoilers, fixed on their boot: not only do spoilers look good, but they reduce aerodynamic lift, in other words, they provide downforce, thus improve high-speed stability and cornering speeds.
> The big debate: Subaru WRX STi or Mitsubishi Lancer Evolution?
This video will demonstrate just how important a rear wing is, as it shows a Mitsubishi Lancer Evo losing its rear wing while traveling at 250 km/h. The result is not very pretty.