I have to agree with Ant...most sponsors operate on a ROI policy...Return On Investment....meaning, will you be able to generate enough interest in their company and products to offset the $$$ they will be loosing givng you the products at the sponsorship price.
It is better for them to sponsor someone with a $100 piece of shit car that goes to shows or competitions every weekend vs. a $100,000 custom ride that never goes to anything... more advertisment= more in return to them.
With the economy in the toilet right now you will be very hard pressed to find any companies offering any kind of sponsorships right now unless you have something really special to offer them...and as much as I hate to say it, you can sometimes still buy you gear on the internet for less than what you can get at sponsorship price, really depends on the company.
Ant offered me sponsorship with him because of what I am building and my overall plans in the future for what I plan on doing with the truck when it is done. To him is is a great opurtunity to help promote his company and show off what his products can really do.
I have found it equally hard to get sponsors from either the big or small companies. The small companies would like to get their names out there but don't have alot of $$$ to throw around and the big companies have the $$$ but are already well established.