I have a forward compartment on my fifthwheel that is big enough to hold my Honda EM3000c (17.3" L x 15.7" W x 18.9" H) (Honda doesn't make this model anymore) which weights 70 lbs. Since I don't have the generator prep, I constructed a platform using drawer slides that can handle up to 100 pounds. This lets me extend the platform and bring the generator outside the compartment.
I oriented the generator so that the exhaust faces forward, away from the compartment. With the platform extended, the area containing the starter cord is accessible. The panel containing the ON/OFF switch is at the rear but I can easily reach the switch when the platform is extended. Fueling is easier when the platform is inside the compartment.
I have a 30 amp extension cord plugged into the 21.7 amp locking plug receptacle via a special pigtail that I made. When I want to use the generator, I open and latch the forward compartment door, extend the platform, plug in the RV electrical plug into the 30 amp extension, and start the generator. This is more trouble that a permanent installation but, boy, is it a cheap alternative. I store my 30 amp extension cord under the platform.
The gooseneck of the fifthwheel provides a good deal of protection if it is raining. My main concern is carbon monoxide building up underneath the gooseneck of the fifthwheel but this would occur on only the calmest days with no breeze.