I had a friend buy a Sherco at the world round last year. Before his son ever rode it, it was stole in his drive way locked as exactly you describe in the back of the truck. I`m a firm believer that vans are the best way to go. No seeum, no stealem`.
I purchased two folding locks from the Yamaha dealer I worked at in 1985. I still use them daily. They are similar to the Kryptonite, maybe stronger. They have a chain like swivel every 8 inches. Easily stored and easy to use. While traveling I also use a cable around a seat base. Bikes locked front and rear. Too bad the Yamaha locks have not been available for years!