When they were filming the other movie with Angelina Jolie in it a few months back they brought one of there film trucks in for us to fix a running concern on it, it was an older Mercedes ML55 with all of that same rigging and everything attached to it and highly modified. The thing was running an aftermarket supercharger with an upgraded air to water intercooler with some crazy HUGE brakes, a full roll cage to support everything and a whole bunch of other stuff.
Talking to the film guys that brough it in they said those trucks need to be able to keep up with the car chases even with the added weight and everything of all the extra equipment so they have some pretty crazy modifications done to em.