Since MRAPs are design against bombs, and have a fire suppression system, the logical way to attack them is with a water filled tiger trap. Simple enough in concept, a deep pit with a waterproof cover that can handle up to about 10 tons of weight, but collapses with more than that. An MRAP weighs about 14+ tons. Plunk. The USMC reported that water accidents of this sort were very dangerous for MRAPs due to their high center of gravity.
Right, simple in concept, but definitely difficult in execution. Can't imagine where you would find a worthwhile spot where you could build one. That's a lot of dirt to excavate and the cover would take some careful design to allow safe passage to smaller vehicles and collapse for 14 ton. Don't forget there is a hatch in the center of the roof.
I was thinking more along the lines of paint ball guns obscuring the windows while sappers cut the air hoses to the air bag suspension. Vehicle out of service. Some way to jam the rear door would be nice (thermite?) as well as a way to rapidly block the com systems (broadband jammer?).
Regards,
GtG