As a person/company who has sponsored racers in the past, you just need to answer one question for me:

How SPECIFICALLY are you going to make me money?

As soon as I read or hear words like "market exposure", "eyeball impressions", and other meaningless marketing terms I toss the proposal in the trash or end the presentation. If you, as a racer, don't take the time to understand my business and figure out how you're going to SPECIFICALLY increase my sales then you're not worth the ink on the check.

In essence, your sponsors are your customers and you must spend time understanding your customer's SPECIFIC needs before you try to sell them something.