Page 124 of the manual says:
"Scion does not recommend towing a trailer with your vehicle.
Scion also does not recommend the installation of a tow hitch or
the use of a tow hitch carrier for a wheelchair, scooter, bicycle,
etc. Your vehicle is not designed for trailer towing or for the use
of tow hitch mounted carriers." http://s3.amazonaws.com/scion.site.p01/scion/manuals/OM12J49U/OM12J49U.pdf
Now we have had a few members install tow hitches for bike racks, don't recall seeing actual towing though.