An older Miata is a great first car to start auto-xing with. Good power, lightweight, and RWD. There is nothing wrong with a teg, in fact, a teg would be my first choice for a front wheel drive car to auto-x in if you are going to run the stock motor. When you are winning or placing in the top few places in your local AND regional races, start looking at modding your car. You can always get a different car, but you have gotten used to the way that one handles. Local stuff is good, but there will always be someone out there on the regional level who's gonna be better. Keep your teg stock and learn how to drive it. Get yourself a set of Azenis and go to town. I promise you can't go wrong with those tires for auto-x...sticky, cheap, and track proven. Other than that, fix the nut behind the wheel before you ever touch the car.