Shelby Griggs has a neat setup...base on the roof of a box trailer, receiver inside, park it and let it run.?ÿ
I have a mag mount for the roof of the truck, used to have a built in mount but that was over the top.
String the wire through a window, leave the receiver and radio in the truck locked up, only the radio antenna, and GPS antenna plus the two wires are outside the truck, of course those can be taken, locate a nearby control point and
As BStrand says, sandbags work wonders.
On soft surfaces when the wind is expected we have some screw in pig-tail/corkscrew anchors ( 10 seconds to put in or take out). One each side of the upwind leg with a ratchet strap round the top of the tripod. Stops it going anywhere.
Only risk with the truck roof mounted method is when the vehicle is not left in gear and the handbrake isn't fully on. I've heard of surveyors coming back and finding the truck has crept three foot down the road.