Our task force uses commercial, off-the-shelf vehicles to get where we're going. A Chevy or Ford pickup with a crew cab and a cap on the back is very versatile. Kept empty of custom gear, they can be customized "on the fly" to meet the demands of the mission. We've worked out ways to set up our trucks as improvised ambulances, mobile command posts, rescue trucks, sleeping platforms, K-9 transports, you name it. They are inexpensive and easy to fix, at least anywhere here in the States. The only thing of significance we've added is a satellite communications and tracking system and wiring the bed for 12V power and communications. The ruggedness is built in by the manufacturer and comes at a reasonable cost.
Take it a step further. Our cargo transports also come with a minimum of modification. We use International Truck and Engine box trucks and Volvo tractors. A little more difficult to repair, but still stock and versitile. Our Logistics guys (the best in the business, in my humble opinion) are in-process of providing HVAC and lighting to the cargo spaces on these vehicles. They'll have them set up so we can do everything from sleep to perform surgery in them, with a minumum of cost. These vehicles are only slightly modified when they get to us, to include area lighting, satellite comms and tracking, extra spare tire racks, and under belly boxes for personal gear. Please keep in mind that the cargo vehicles are not used primarily for searches, but do take up positions in forward areas and may be tailored to the mission at hand.
Spunky