Increased structural integrity with structural foam

[hotroddr]

After thinking about this for a while i searched online and found out that this has been done and is being done in some new cars. Filling structures with foam increases the strength and the ability to absorb impact of that structure.
I am going to do this on my truck in order to have more rigidity and safety without significantly increasing weight. I was wondering if anyone here has filled A/B pillars, frames, or roll cages with expanding structural foam, and if so, is there anything I need to know about doing this