im just pulling common sense out my ass but:

to get sponsorship, you want to stand out in a crowd. you want to be the fastest...the show-iest...or the most whatever-ist. then you can go to a company and say...hey, my car gets attention. if you sport a banner on my car, your company will get attention too. i will sport the banner if you do give me a discount on parts....or whatever.

then of course there are probably high expectations after you get sponsored. :dunno: