Questions about running generator in back of truck

I've run my Yamaha 3000 iSE in the back of my truck, uncovered, from 2011 to 2016. My Champion 4000 watt now sits there in its place after the camshaft seized (I loaned the generator to someone... big mistake.)

Nothing wrong with it being in your truck, although the bed does cause echos of the noise.

Just make sure to secure it with at least two chains or a box as pictured above.