My theory for putting it behind the radiator is as follows:

The SVO is a very rare car. The majority of owners want to keep the car a collectable by not hacking into things or doing modifications that are not easily reversed. Putting the it behind the radiator makes routing all the proper plumbing and whatnot very easy.

I saw somewhere where a guy had a pretty nice looking intercooler mounted behind the radiator. It was near the bottom, but the lower end was kicked out so the intercooler layed at an angle. Behind it were two small fans to help pull air from whatever comes up through the bottom of the motor compartment.

I assume people are seeing decent gains over the pint sized stock intercooler. I completely agree this is not the most effective placement of an intercooler...but it must be better than that tiny thing Ford put on the car.

And like Dave said, there isn't much air getting through that front bumper. Although I really think that bottom opening is adequate for a FMIC. If I have to hack things up to get a FMIC in there, I'm just going to forget about it and figure something else out. As much as I want to enjoy this car, I also want to be able to keep the resale high. Worse comes to worse I could put a nice liquid/air intercooler...the heat exchangers are much smaller than a FMIC and there is plenty of room under the hood for plumbing.