silvercoinrn - Don't underestimate the appetite of IRS & the state tax depts. When you win a prize from any 'above-board' contest like this one, the entity that gave out the prizes is required to report the prize values and names, addresses, & SS#s of winners to the IRS.
Whatever you won is considered to be taxable income and will be treated as such - just like a paycheck. It doesn't matter whether you won cash, a car, gold or a pile of clay.
They're very helpful, though. You don't even have to contact them. They'll contact you - with a bill that'll include penalty & interest charges, since you didn't file the legally required return (with payment of the tax due) on time.