Yeap I simply "chain and lock" it to the rear spring shackle. If you get to a TS in the summer down in the south, you will see this setup all over. There is a sprinter rounding around with a rooftop mounted genset, inside a metal box...too much BS for me, climbing a ladder to service and fuel it...not for me..i am into easy....
As greg said, the RV places do have an enclosure that they use, you might look into that. As for the rear hitch mounts rack, there are a few that "Swing away" when you need to open the doors, again, too much BS for me...
And as for adding a "external fuel tank", there is no need to add a eletric fuel pump in most cases, these type of generators/ inverters have a "pulse fuel pump" all you need to do is splice a "T" into the original fuel line from the original fuel tank then hook up the fuel line from the external tank. Most of
One thing to keep in mind also when buying one of these, if you are planning to use it in CA., it needs to be CARB compliant..and yes they make them to fit those recommendations..without that feature, you can't use it in CA.
The CARB Compliant gensets are a "closed loop", fuel circuit and are non-vents..so all fuel vapor is circulated back into the fuel tank so if you add a external tank, make sure that you do NOT use a fuel shutoff valve between the 2 tanks, you need that closed loop sysytem for the engine to run properly....
Another way to add a tank is to do it as a "Gravity" tank by drilling a hole in the gas cap and sealing a fuel line from the external tank into it, personally, id stay away from this, but i have seem a few doing it that way....