There are a million ways to answer this question, but almost none without knowing what type of business you are in...As someone who makes his living doing this, I will try to shed some light here...
The first step, is to come up with a budget of what you can afford to spend on a single event...This is certainly hard to do without knowing more, but at least it will give you some sort of starting point...
The VERY next thing you need to do is come up with a set of goals...If you are willing to spend $5000, $10,000, $50,000, $100,000 or more, you need to know SPECIFICALLY what you want out of it...Brand exposure, for a single event, is NOT the answer...For example, in the Tampa market, lets say you are in the business of selling rebuilt transmissions to auto repair shops, then here would be a good strategy...Look at all of your customers that bought transmissions from you in the last year...Lets say you had 200 shops in the region that averaged 10 transmissions per year, at an average cost of $600 each. That would mean that you sold 2000 transmissions in Tampa that year for $1.2 million in revenues...That being said, here is your goal...You come out with a new program for your customers...If they increase their yearly orders by 20%, so this year, to qualify for this new program, they needed to order an average of 12 transmissions to qualify, and whoever increases their orders the most, gets a grand prize of a 20-person hospitality event that THEY could use to entertain their fleet customers, family, etc...AT the Gator Nationals, along with the name of THEIR shop as a Major Associate sponsor WITH your transmission company on the car as the Primary, then this would work...Everyone else that signed up for the program and met their goal was a guest of yours at a hospitality event...This is a REALLY exciting promotion...These "little" corner repair shops that are run by "motorhead" mechanics, who are most certainly HUGE race fans, have the ability to have THEIR name on the car...WOW! They will work hard to win this....Here is how you pay for it...
You sold 2 more transmissions to the 200 shops that you have as customers, for a total of $120,000 in increased revenue. Out of that, you take 15% of it, and apply it to the cost of this program, giving you an event budget of $18,000, in this example...But really, many shops did more than a 20% increase because they started trying harder to sell more transmissions to their customers that brought their cars in....They really wanted to win that cool prize of a 20-person hospitality ordeal that you put up...
Another thing that you do, is you hold a contest with your sales people..The grand prize is a $2500 bonus and a private dinner with your driver the night before the event. The objective is to see how many new accounts they can open between now and the event....Follow me here? This certainly increases business for you....
A third way, is to leverage the sponsorship with YOUR vendors...You say to them that you enjoy buying their transmission parts, and now you are ready to expand your business and start buying more transmission parts from them, and you show them how you are going to do this...You also let them know, that you need their help, and in many ways OTHER than your increased orders, this could certainly help them too..Maybe THEY are an associate sponsor with you and throw $10,000 towards the budget, and in turn THEY bring a few customers to the event...see where this can go..?
Your vendors, that sell you parts, certainly want to keep your business, as well as see it grow...Getting involved in this deal, using this example, is easy to do, and it certainly solidifies a major account relationship for them....
There are a million different scenarios here, but if I knew more about what you do, I'd be able to help you much more...The bottom line is this...you will certainly pick up more customers because of the exposure of your car at the event, but if planned properly, the deal should make sense to sponsor that car BEFORE the car even hits the race track....THAT, my friends, is how you stretch it out right...
I hope this helps a bit...