Not really worth it. I have a 93 Volvo that I bought about 2 years ago and plan on driving it until it costs me more than if I were to have a payment. So far, it has been an excellent car. In fact I had a 93 S10 pickup that I owned for the past 6 years until it was totalled recently when someone pulled out in fron of my wife. I would still have it if it weren't totalled. Oh well, we needed a bigger vehicle anyway. We bought a 01 Tundra. It is nice. Big enough for us two and a two year old. I have always bought my vehicles with cash with the exception of the Tundra. I buy used to get the best deal and keep them for as long as I can.
Keep the car. It is what it is, a car. Transportation that loses value. It is not a house that goes up in value. Keep it unless it just kills you not to have the car you really want. A couple of years down the road, you will likely owe for the Miata still and want something else and then get stuck in the vicious cycle of having a car payment for the rest of your life. Not my idea of fun.
