[aerohead]

Modmonster,as Big Dave has said,it really does depend on the particular vehicle.And as Tango Charlie has mentioned,as the full bellypan is always favored by die- hard aero guys (and gals!),if you can't go that deep,the the airdam can serve as a palliative.------------------------ Here's the rub for you.Adam Opel AG,who developed the Corsa,does a lot of wind tunnel development with their cars,and I suspect that they "looked" very hard at both it's nose and underside.The car should already have a form of front airdam integrated into it's fascia.Also,being a uni-body type vehicle,lacking the deep recesses of a body-on-frame chassis ( as in a pickup truck,or truck based SUV ),the platform no doubt,has already received many small refinements to shield undercarriage components from the air. Auto makers have done a lot of this sort of "unseen" development since the 1970s.-------------------- So,this area of the car may have already seen much "optimization" and might not "show" remarkable improvements from more "radical" modifications.------------------------------------- For some,it comes down to,"I have to know!" And they just jump in, with a leap of faith.I'm willing to lose money on my own experiments,although am reluctant to waste other's hard earned money.--------------------------------- So where does this leave you? If you can find my installment on aero mods,% mpg change (under vehicle modifications)in the archives or earlier pages,I've listed all the quantitative values I have for these kinds of mods.If you'll study those numbers,it may give you some insight as to what you might expect with the Corsa.-------------------------- If you run into a snag,let us know,and we'll jump back in.Good luck with the project!