If you want to write-off your racing expenses, you've got two options:
1. Make your racing part of the marketing program of an established, legitimate business. Your truck, trailer, bike are all advertising media. This business will have to be your own, unless you've got a REALLY cool boss who will work something out with your employer.
2. Start a racing-oriented business (i.e. consulting). The problem here is that it will be difficult to show a profit. It can be done, however, with the help of a good CPA. The rules for showing a profit are actually as follows: For the seven years preceeding your tax audit, if you showed a profit for at least two years, the IRS CANNOT argue the legitimacy of your biz. You've won. If, however, you don't show a profit for at least two years in this period, the IRS can call into question whether your "business" is a business or a hobby. It doesn't automatically mean you've lost, but you've got to show a LOT of proof that you're trying to show a profit and it's a real business.
And, if you never get audited, it doesn't matter. About .5% of all 1040's get audited each year. :mad: