Remember this thread?
http://www.njfboa.org/forums/showthread.php?t=32227
Build your foundation of success and exposure first before taking on bigger racing opportunities.
What are you doing, right now, to get sponsorship? Simply racing, and even winning, isn't enough. You'll be seen as a lucky newbie, not even a rookie because you won't have other events to point back to. Build your credibility first with people who may have little to do with racing, but a lot to do with sponsoring people and events. Once you're seen as a stand-up guy who can get exposure wherever you go, then seek sponsorship for a new endeavor - racing.
Pepsi, The Home Depot, US Army... have nothing to do with racing other than sponsoring teams. Their names are splashed across lots of vehicles, because they believe in the teams' (and drivers') ability to GET NOTICED. Its all marketing, not winning a stupid race.
Get local sponsorhsip for local events first. Find the charities you are willing to invite to events that YOU are already paying for, then invite the local newspapers to cover that GOOD CAUSE at the local race track.
Get out from behind the steering wheel and talk with people about what you'd like to do and how you plan on doing it. Friends, family and business acquaintences will usually be the best people to talk to first since they'll give you the most amount of time to sell your dream. After that, and once you've gotten that exposure, THEN reach out to the folks you don't know, and sell them on the same dream - using the interest, exposure and success you've already had. If companies can envision the exposure you can bring, they can envision the value of the sponsorship you are looking for.
Once again, good luck!