The IFAV is a German-built light scout truck built for the German Bundeswehr (Army). The USMC recently arranged to take delivery of 62 of these vehicles as in interim fast-attack vehicle until their next one is ready for service. Presumably the Chenowith Desert Patrol vehicle is being phased out. The IFAV is built by Mercedes Benz; the one pictured above is on loan from the German Army for testing purpose. It has a 90 HP (66kW) engine that can drive it up to 80 MPH (130KPH).
USMC article
German Army Fact Sheet -In German, use Babelfish