Yup, exactly. Do I buy a 2007 Frontier because it's 2 years old and theoretically cheaper? Or do I get a new fresh 2009 model with next to nothing on interest and a ton of cash on the hood from factory incentives? The new model costs the same as the 2 year old one with 50k miles on it...
Again, depending on the make and model,
this may be the best time to buy a new vehicle vs a used vehicle. The factory incentives
may offset the money saved from buying a depreciated car (used). The re-sale value
may also make the new car a more attractive proposition, especially if the car just went through a new generation and the used car will have an antiquated style when you attempt to sell it 5 years from now. Therefore bringing in an even lesser amount.
A car is by no means an "investment", but can be treated as an investment by trying to obtain the lowest cost, highest value vehicle.
Most of the time, a 2 year old car has taken most of the hit on depreciation. You can pick up very low mileage cars that are 1-2years old and assuming you have a good credit score, you can be thrifty and shop financing options. This is generally the most cost effective.
Ian needs to decide what his goals are with this car, if he's going to play the number crunching game and view this as an investment.
I buy CPO'd because I burn through cars. I put 30,000miles + on my car a year. I allow the first person to take the hit on depreciation, pick up a car with 20,000miles on the clock and run it into the ground over the next 3-4years. Rinse and repeat.
This is most cost effective for myself. Now, if I did not drive so many miles, I'd negotiate a lease. I'd lease because I generally like to get a new car every 2-3years. If you like flipping cars that quickly, you can usually get in and out of a lease with least of a cost and none of the time required to sell the used vehicle.
My girlfriend does not drive many miles and plans to keep her car for 5-7years. She'll do better off by buying a practically new CPO'd vehicle that is the current generation or by buying a new car with heavy factory incentives.
If nothing else, I hope this provides you with some insight into various scenarios. Just like anything else in life, the purchase is really dependent on YOUR needs.
So pick the scenario that best fits you, but I'd warn you to be honest with yourself and not to commit too much money to the car. You'll certainly regret the purchase down the road if you have to pass up the house/vacation/electronic device/wedding/whatever of your dreams because you're tied to a car payment.