I bought my ACR from a guy in Atlanta, and I live near Philadelphia. Yes, I drove 14 hours to buy a used Neon.
First, I carefully checked the guys credentials in the online community. He was also into Miatas and the Miata community said good things about him. After some discussions online we arrived at an attractive price and I flew down to pick up the car.
As we were leaving the airport to go to his house, the clutch cable broke. We got the car towed back to his house, and he tried like hell to get a new cable for it that day. It didn't work out, and I ended up flying back home with no car.
Then, a week later, he called me back. He'd gotten the cable replaced and he split the cost of my first round trip with me. I flew back down, picked up the car, drove it home without a hitch. I've been driving it ever since.