I just finished minivan shopping. I had been on a waiting list for a Toyota Sienna since June and gave up waiting and bought an Odyssey. I think I got one call during that time, but it was for a trim level that I wasn't interested in. If you're really set on a Sienna, if you do some searching, you can find spreadsheets showing allocations being delivered to Toyota dealers. I'd guess the only way to get one quickly would be to call lots of dealers, including dealers outside your area, and be willing to pay a markup over MSRP.