Alan Jackson surprised Zac Brown with a 1966 white Cadillac El Dorado convertible prior to the Zac Brown Band's concert on Wednesday night (Dec. 29) at Nashville's Bridgestone Arena. Jackson told USA Today the car was a thank-you gift for being invited to sing on the Zac Brown Band's latest No. 1 hit, "As She's Walking Away." Jackson also sang the Grammy-nominated hit with the group during Wednesday's concert. The Zac Brown Band will conclude the year with a Friday night concert at Philips Arena in their hometown of Atlanta.