Financially do you think it is better to buy new or Certified Pre-Owned vehicles? Does it effect interest rates? I worry about being upside down on the loan due to the immediate depreciation of a new vehicle off the lot. On the other hand it would be nice to be the first owner of a vehicle. What do you think?
I think you have to decide what is best for you. Most manufacturers have special financing for CPO's, so the interest rate vs a new vehicle will probably be similar. It depends on what you are looking for. Do some research into the specific vehicle (there are forums like this one for just about every make you can imagine). when I looked into it, I found that lots of people felt the CPO status may not be worth it (depends on make and model you are looking at).
I recently bought a new vehicle, and had my heart set on a CPO. I found that for the same price for a CPO, I could get a brand new car. The car I bought wasn't my first choice, but in the long run I felt I bought a better, more reliable vehicle.
There are always tradeoffs. My last vehicle was a CPO, and I had no problems with it and never used the warranty. The one issue I had was not covered by the CPO warranty (that is why I suggest you do some research into what the CPO warranty actually covers, and whether it is a good buy for you).