Structural Foam for chassis stiffening

My brother got me thinking more about this and as a mechanical engineer, it peaked my interest. So I've been researching using expanding foam, in key areas of the chassis. Many OEMs already use several types of foams to reduce NVH, improve collision performance and stiffen the chassis. BWM even used rigid foam to "fix" their frame cracking from fatigue.

Looking at my 72 Swinger, it appears the rockers, along with the upper and lower A, B and C pillar joints would be perfect candidates for a rigid foam. Most foams are fairly lightweight(8lb/ft3) and somewhat benign in terms of "installation."

Just wondering is anyone thought of such a thing on their A-Body. I figured at the very least, the foam could help with NVH.

Here are 3 SAE papers I found from Chrysler, Mazda and GM testing the improvements of structural foam. The Mazda paper is quite interesting.

http://www.mwsmotorsports.com/z32/foam/MontanaFoam.pdf
http://www.mwsmotorsports.com/z32/foam/1999-01-1785.pdf
http://www.mwsmotorsports.com/z32/foam/2001-01-0313.pdf