The towing capacity of the 2021 Sienna is rated "up to" 3500 lbs but only if equipped with the "towing prep package" which includes a heavy duty radiator and oil cooler. I'm not finding any such package in the options, though. I do see a hitch but there's no mention of the other two items in the towing prep package. Anybody know what's up? Those with the tow hitch, were the heavy duty radiator and oil cooler also included?