Something I noticed the other day - an older model Hyundai Accent with some sort of rear diffuser (or perhpas, an attempt at a rear diffuser) molded into the rear bumper.
I've noticed a few other budget cars with this (some trims levels of the recent Kia Forte Koup, for example), and it got me wondering "why?". Does it make a significant difference in aerodynamics, and therefore fuel consumption? And if so, why are most of our cars' rear bumpers just smooth and featureless? Or is it really just for the sporty look?
Oh, and to counter the strong sedative effect of that 4-door Hyundai, here's an F430's butt to get your blood pumping again: