I've heard the advice about how you minimize the depreciation you pay when you buy a car that's ~2 years old, and sell it when it's ~4 years old. Granted, you're getting a car that's "new to you" every 2 years, and it might be the best way to minimize the depreciation hit. But, you do have the concern of 'how did the first owner treat it?'
And, if you're looking at the HiPo v8, you have to figure it probably won't be available until Fall of '09 at the earliest. If you try to wait until it's 2 years old to buy a pre-owned, that means waiting until
late 2011 or early 2012 to get a Camaro. And I just can't see myself being able to hold out that long! So, I find myself with a 4-year old car that is paid for, and my more realistic timeframe for a Camaro to be about 2 years from now (when the HiPo is initially available). If you believe the pundits, my best course of action would be to replace my current car with a 2-yr old car and drive it for 2 years. But it's so nice not having a car payment right now!