The prop_physics entity checks if the model has been set up as a physics prop by having a prop_data data block in it, and there is no documented way of adding it. You can get around it by using the prop_physics_override entity instead.

thanx for the Info, i tried prop_physics_override , what now happens is, i can grab it, but after i release it i can't grab it again. hmmm

That seems to be an issue with complex collision meshes. Try checking the Convexify flag in the properties for the collision mesh in the model editor, or try making a simpler one. Meshses made from a single convex hull seem to work the best.

Thank you very much Rectus! Checking Convexify did it! :D
Incredible, now i can fill up my Destinations with tons of stuff hehe