Originally Posted by BrianW
If you are using the body mounts and your awning gets hit by a big wind gust they could theoretically rip out of your van's sheet metal, which would not be fun.
More likely break the plastic pins that hold the legs to the top - which I reckon is why they are plastic..
That said, I've never seen a real benefit to body mounting the legs.. I generally try to camp on level ground, and while the legs might be more sturdy if they are mounted, if I need that I use a tie down and mount it to a cooler or something, or take the whole awning down.