Rocket1970. My car will be four years old in January. It has never needed vax all these years. If you apply vax yourself, it is a time consuming and tough job. If you get it done from workshop it costs at least 500 bucks. On black colour you need vax every three weeks, so imagine the cost and time.
By the way I applied wax (not polish) only yesterday, because I had bought carnouba vax from Metro last month and wanted to remove a scratch mark on front passenger door and then I did the entire car and it was after nearly four years, that I applied wax, just for fun and checking.