I know I know, this sounds ridiculous, but I think it could do some good for our cars.

Anybody know if there would be much if any benefit for making a smoother underside on our cars? Our cars aren't exactly the most aerodynamic things on the road, so I was wondering if there was something simple we could do to our cars to get a little bit cleaner aero. I was thinking of fabbing something like the picture below, but wanted to hear some opinions first. I know that it probably wouldn't do much until after 80mph or so (if at all), but sometimes that darn gas pedal gets stuck

underside of a subie wrx with an aftermarket under tray


Rough photoshop of what I'm talking about on a Brian's SN95

without:


any good pictures of a mustang underbody would be appreciated :)

I'm aware that this would make oil changes a little more time consuming, but that doesn't bother me.

What are some potential concerns you guys could think of? The only things that come to my mind are - it coming off while driving as well as the changed airflow inhibiting some things to cool like they did before.