I wonder where the big mechs come from then hmm, make them on the planet, but can't take them with you? Or maybe... just maybe.. you can fit it in your pocket!
I was thinking more along the lines of a dematerializer that would break down your vehicle into a compact form of particles to store on your ship and then reconstruct it on the surface of the planet you need the vehicle on.
Or just print your vehicles and skip the dematerializer entirely(Does the 3d print scan and break down items on it's one?)