I agree when the water tank is full and I do not have an onboard generator at this point, but hope to find one that will fit in that size opening. If you have any knowledge of a aftermarket generator that will fit in that hole it’s probably only 18 x 24 maybe 16 to 18 inches deep thank you for contributing. I appreciate this site. I’m looking at the aftermarket airbags to fit this model of mini Winnie motorhome on a Toyota chassis, and maybe even the Bent ad on Spring that attaches to the leafs along with new shock absorbers all the way around.