"Take the loathed SUV as an example. Let’s say you went out and bought a $50,000 SUV in December 2008. If the SUV is at least 6,000 pounds, you can immediately write off up to $25,000. You also get to take bonus depreciation of up to 50 percent of the remaining $25,000 that wasn’t written off under Section 179. That’s an additional $12,500. And then you can take ordinary depreciation on the remaining $12,500. That translates to another $2,500.
Add it up: You can write off up to $40,000 of the purchase on your 2008 tax return."