Things to buy at Wal-Mart (WMT): paper towels toothpaste jeans and a new car.Yup Wal-Mart now sells cars. The Live X Auto Exchange an online trading link set up pilot operations in Wal-Mart Supercenters in the Phoenix metropolitan area.The Good Old Boys with MBAs in Bentonville Arkansas are testing the auto business at the right time – many dealers can’t line up credit in the market crunch and face closure. If all goes well Wal-Mart may step into the void. Selling cars online isn’t new. CarMax (KMX) and AutoNation (AN) have done it for years. But Wal-Mart adds its ...