I've posted my progress to date of my "hard to keep the pot boiling" rear bumper build. Very early days yet.

http://shufti.wordpress.com/2013/08/01/vanagon-rear-bumper-build/

I'm making it from 1/4" 6061 aluminum . Why aluminum? because I like the stuff, nicer to work with than steel, cleaner too. And I tend to contradict Colin Chapman's dictum of "simplify and add lightness" so starting with a lighter material will help keep the overall weight down :)

alistair