Charlotte is 2-2.5 hours from Virginia Int'l Raceway, which is just across the NC/VA state line about 10 miles east of Danville. You're also less than 90 minutes from Carolina Motorsports Park down near Kershaw, SC. I've been to VIR a few times and it's an excellent facility. In its Grand East configuration it's one of the longer road courses you'll find, at 4.2 miles. Never been to CMP but I've seen plenty of video. Too many boring straight sections and not enough turns or technical areas to make it really interesting for a Miata, but cars with 300+ hp and good brakes would have plenty of fun.