I haven't got a clue about the cars, but I suppose there are Austin's Rover's, Ford's, Standard's Vauxhalls, and Morris's there. The car park is definitely the Big Top site on the corner of New Street & High Street. The YMCA information booth is in the foreground ans over the back of the car park you can see Union Passage with the remains of the Central Arcade. The photo was probably taken from the roof of either the newly reduced in height Stevens Bar or the Milk Bar at the junction of High Street (Bull Ring) and New Street, where the Rotunda stands today.