If you wanting a faster warmup than idle rpm gives, try this: with the parking brake on and left foot firmly on the brake pedal, put it in D (not P) and floor the gas pedal and hold it. ICE will run at its highest pre-set RPM, not redline, because the gas pedal is "fly-by-wire" and not a direct connection. Procedure is often referred to as a "force charge" as the battery will get charged during this. Since this means sitting in a cold car, not the most elegant solution. Although I've done this on previous hybrids, I haven't tried it yet with the Sienna but I think the procedure is the same. We use the 10 min. auto-start function on the fob instead.
If you're just wanting to make zoom-zoomy noises to impress the ladies, dazzle them with your personality instead! <jk>.
sitting in park, you can at least start the motor, and rev it to high idle to charge the battery. start pressing the accelerator pedal down, it will first start the ICE, and then if you push it further down it will rev to high idle. thats it. I use this after oil changes to circulate the oil before i actually go anywhere.