The Curt Hitch # C11421 that fits your 2016 Scion iA is a Class I hitch with a 1-1/4" receiver, which means you need a bike rack with a 1-1/4" shank that is compatible with a Class I hitch. Please note that you are also limited to carrying two bikes with a Class I hitch.
I highly recommend checking out the Hollywood Racks Trail Rider # HR200Z, which uses padded hooks to grasp your bikes by the top tubes and adjustable wheel mounts with straps to secure your rear wheels. It has a mast which... view full answer...