This not a competitor to smart. Plus, I bet the rear end is disguised. It looks like an add on to keep the silhouette secret.
I'm also betting that the Toyota IQ is not going to pass US safety standards. If you ride in the back seat, you are only a couple of inches from the back. Your head would touch the rear window in a crash.
Imagine what a rear end collision would do to a human body there. Just my thoughts, but since that is where a child would be (in the 1/2 seat) who would risk it?
The IQ might be OK for putting around in town or even on the highway, but the back seat really seems dangerous.