You don't have to look too far on EcoModder to find people who have made "aggressive" mods to their vehicles that require more attentive driving or otherwise changed behaviour to accomodate said mods.
Examples: everything from pickup truck bed covers, to passenger mirror deletions/relocations, to full boat tails.
Well, Chevy is now offering to replace the aggressively "deep" (low) front air dam for Volt owners who aren't happy when it contacts the ground or other obstacles in their driving environment/circumstances. It's possible the segmented air dam can separate, leading to flapping at highway speeds.
The original dam: from CFG's album
Has about 4 inches of clearance, according to Green Car Reports.
They didn't say how much shorter the new dam is, or how much it affects the car's aerodynamics.
Looks like the replacement dam (above) is roughly an inch or so shorter.
Source & more information:
2011 Chevrolet Volt: Air Dam, Display Issues Fixed By Dealers