Its not based on how much you owe at year end, its based on how much you paid in. If you are married, the standard deduction is $24,000 ($12,000 if you are single). That means you are probably paying taxes on any income above that $24k (or $12k). Based on current tax rates, a couple making $58k a year (or a single person making around $45k) would pay $7500 in taxes. Either way, I would assume someone in the market for an automobile between $40k - $60k would make more than the amounts above. Granted if you have kids, the formula changes a bit. And you may have some individuals who are retired or semi retired with a large nest egg and little to no taxable income.