Not a prang but lost a wheel when we hit a pothole (that was scary!), back end smashed in whilst parked up one day, all hub caps disappeared on one journey. Could only select two gears by end of the trip! Some experience but great memories. The roads were just unbelievable.
On top of standard Insurance, I took out my own Enhanced Roadside Assistance for around $2.50 a day. http://www.enhancedroadsideassistance.com/index.aspx
I've spent some time in Alabama. You won't need to pay tolls in there, the highways are excellent, long, boring, but excellent and they have prison chain gangs to keep them clean which is nice ;-) The roads off the highway are also generally excellent, devoid of roundabouts but you can quickly get into areas where they stop being cared for, like they are unadopted roads so just keep an eye out. Spent some time in Georgia too, same as Alabama except around Atlanta where the highways get enormous and cars are coming at you from all directions, scared the hell out of me when I first encountered it.
I picked up the car at the airport but used public transport around Atlanta yesterday and was very glad I did. The traffic looked mental, and that's from someone who drives in Russia! Hitting the road today, and generally planning to keep to the back roads. Should be more fun, as planning to do some small redneck towns on the way down to New Orleans. Which should be fun, apart from the motels, which I expect to be ropey as hell, but probably quite a laugh, just for a night or two!