You can also catch the bus to the TTC and make the short walk to the Polynesian. On a recent trip, I wanted to return to the Polynesian and the rest of the troops wanted to stay at AK a little longer so I took the bus back leaving the car for them. I waited a long time at the stop with a gentleman on his way to the CR. He had been there for some minutes before me. I really wished I had gone to the TTC because I think two TTC buses came and went before ours. Unfortunately at AK, the two stops aren't close together. If I remember correctly, the TTC stop is close to the beginning of the loop and the Polynesian one is certainly at the end. Next time I would wait at the TTC stop and if a Polynesian/CR bus came first, try to hightail it across the top of the loop to catch it.
However, if you're leaving near closing I'd probably wait for the CR/Polynesian bus as it won't be as crowded.