Keep a copy of this article in your truck for at least the next few months.
http://www.irs.gov/irs/article/0,,id=148123,00.html
And this one:
http://www.epa.gov/katrina/faqs.htm#11
It will save you in the off chance you get inspected. Since you drive a Class III truck AND you live in the People's Republic of Kaleefornia, you might get pulled over, but the risk is very, very low.
-Steve