Dirt on the unprotected area under the pedals is normally not a big problem, and it might not happen often, but it could be irritating if you are anal about how your interior looks. The "dead pedal" area is prone to collecting all kinds of dirt, even on a stick shift car where your left foot is on the clutch pedal frequently for stop-and-go driving. That being said, I'm not sure any style of currently available floor mat would adequately cover the "dead pedal" area.