I would think you could do something similar to the manually emplaced booby traps I created for myself in the Viet Cong OOB. I used an AT-gun class of some sort IIRC, set the size and speed to zero and the crew to one, and gave it any number of weapons (in this case you could just create an IED weapon with range 1). I also used the spider hole icon, which looks like disturbed earth.
It gives the weapon a bit more range than it should, but allows placement of explosives along the roadside that are inconsistant in their detonation and effect, which is pretty true to life.
Someone else talked about how one might go about creating a VBIED in this thread too:
http://www.xtreme-gamer.com/forums/s...ad.php?t=41540
Just some idea.