in the past we have just used plain old garbage bags if things get really bad with wet and dirt
2 kids wife and I and and a dog in a FJC

so tight beyond belief
lucky here the rain comes then goes and dries off
when we had our trailer we had some rain soaked days day after day ?
I used to do a lot of bicycle touring

so being rain soaked was part of it
on our roof is our bags our tent which is large and a few other misc things
inside is our IGT tables fridge and some misc camp stuff that fits in spaces then outside on rear rack thing is propane and jerry cans
our problem here in AZ is dust ! anything on the back of your rig is insane dirty
I have to off load everything from our rack
you are not alone
some spots we go there is no water so you have to bring enough to last which is a pain in a way ? I do miss the tanks on our trailer
so we might need 4 or more jerry cans of water
loading 4 bags 4 pads 4 chairs 4 bags of clothes is not as easy as just 4 bags

and not having the bags to heavy
while this has been a expensive setup I do like that it weighs less over all

have to weigh everything one day
next trip we are going to leave our small lifetime table at home ? we love it and use it but going to see if we can get along with out it