When I select "Beginn Patrol" at the Quadbike at Maxwell u can leave with it the base.
I made the side mission "Crimson Tide" in the small village at the East of Stratis,
killed the 5 or 6 A.A.F. Soliders,
put all the U.S. (or N.A.T.O.) weapons from the dead Soliders into the Quadbike until it was full.
I got back on the Quadbike and drove back to Maxwell.
BUT I was on the Quadbike when it said "Moving closer towards the Base will end patrol" I didnt left the Quadbike and the Game said "Mission Successful"
(It loaded the "Maxwell" mission and I was in front of the Base Entrance, but I cant move, change to 3rd person , dont have any gear like a Map or something)