As to the original question, Nope, almost certainly not. Although I haven't had an A3 and don't have a new A1, the Golf 7's armrest (just got rid of my Golf R) is noticeably wider than the Polo's (I have a Polo GTI+). The Golf's is the same as the A3's, and the (new) A1's is the same as the AW MK6 Polo's.