Now that.....I think is a clever solution.
Pity my Engal is too long to do that in the my 130 twin cab:( .....I have mine laid on the floor infront of the rear seats. It takes up the space of one imaginary rear passenger who I've had in the four years of owning the truck!
I'd be inclined to keep the slide mount though....easy in and easy out solution without faffing about.

