i found it;
a 105mm round under a rock pile on the roadside, wired to a remote battery:
Big K,
This was and IED setup from back in June or July 2003. This is pre-school stuff compared to the graduate level IEDs that can be found now. A 105mm round detonated on the roadside against a Stryker might flatten 1-2 tires and scratch a tiny bit of paint off. Buried in the road, you'd have some severe concussions inside the troop compartent and probably blow an axle, but not much more.