Spoilers can add extra down force and help high horsepower cars with rear wheel drive keep traction. This won't be a performance modification on the Honda Fit, more so an Appearance mod.
You want your fit looking its best, and a nice sporty spoiler will do the trick.
Which ever way you go with a spoiler, make sure it flows with the rest of the Fit's body. Body lines that don't "Fit" will give your car uneven lines. Keep the body lines clean, whether it be a mild appearance you are looking for or a Custom Kitted Fit Look.
Factory Sport Spoiler
N1 spoon style spoiler
Noblesse roof spoiler
Choose the right Spoiler to flow with the styling you are adding to your Custom Fit.