As the owner of two cats, I'm going to have to side with the cats in this case. It's YOUR fault you didn't cat-proof it

Check this idea out. Get some chain, you decide on the "daintiness" of the size of links you want. Get enough to hold the door open at the max, and screw one link into the door, and screw the other end to the inside of your cab. It won't stop the "crap, it happened again" factor, but it'll stop it from dropping all the way.
If you want more security, add a second chain on the other side.
They make hinges for this, but they will be expensive.
Check this one out....$26! It's a lid support/hinge.

They also make cabinet hinges that open a certain amount of degrees, that may have been a solution.
One other solution....make the slot in the bottom of the door, or on the backside, since your juke's on wheels.