Toyota does offer a trailer hitch for your HiHy. I got one installed from the Toyota dealer about a month ago. There are two options, one with and the other without the wiring harness. I ordered the hitch without the wiring harness, but the installer accidentally installed the wiring harness and I got that option for free... I think that was about a $100 savings. On my invoice, it has some part no (?) 16TOZ, not sure if that helps.

The hitch is great, well worth the money. I bought a Bauer bike rack and mounting it and my bike to the HiHy is like night and day compared the same exercise with my traditional rack that mounted on the back of my passenger car's trunk. Literally a few minutes to mount and secure the rack and then do the same with the bike.