I made a engine belly pan for my Civic. I was apparent that mass amounts of air were coming up from under the car. Ive owned many FWD cars in the past and NONE had this much trash carrying underhood air movement. Not even our current Accord has as much.
The pan helped a whole lot. The engine bay now stays very clean. Even cleaner than the Accords. The car doesn't have grill blocks as of yet. But the engine belly pan really helped. Its like night and day.
I was hoping that it would help with air drag. But I cant tell its done a darn thing for the mpg. The engine bay stays way cleaner. and I like my engines clean.
psy