Front air dam Mercedes 300d
 

I blocked off the grill and now I'm thinking of a front air dam. Lots o stuff under the car that may benifit from one. Here is a picture of the front under side. Let me know if this a dum idea.

Don't ask, just do.

Here is a pic. Yes. I'm going to do it. Just want to get best advice before I start

advice
 

Not sure how 'deep' you want to go,but if attached to the front bumper,below the rubber stripping,you could wrap the airdam all the way around and back,near the front wheels,to create an integrated air deflector there,as is done with contemporary airdams.This would prevent the air from colliding with the outer face of the tires,which are traveling downwards at road velocity.Very dirty!

Not a dumb idea to ask first.

Not a dumb idea to add an air dam.

It's hard to go on just a single picture of a typical 300d. What is the use case IOW where and how do you use it? Rally-cross much? Are you going to stance it?

It appears to have a vestigal air-dam already, so do you have mounting holes? Are you adverse to altering the bumper?

Rather than the conventional conveyor belt style, you could make a diamond-plate skid pan from the bumper to the front crossmember and put L-shaped scoops under the ends of the bumper so they form a converging duct with the front valance to energize the air striking the front tires. Sort of an anti-spat.

edit:
well, that's a lot of hand-waving. :)

I got this far and foundered on not wanting to drill holes in that shiny bumper.

http://ecomodder.com/forum/member-fr...r-curtain1.png

That's an early bumper over-rider upside down under a later bumper. Here is some CAD (cardboard aided design)

http://ecomodder.com/forum/member-fr...r-curtain2.png

I was intending to close the L-shape to the under-rider. You might notice the gap-filler at the back of the duct; the Superbeetle has a pronounced curve to the valance.