Crash tested carrier for small dog (less than 10lbs) that doesn’t require the use of the shoulder belt or harness?

Hi all,

I'm looking for recommendations for a crash tested carrier for my pomeranian that doesn't require the use of a shoulder belt or harness (he's currently too small for the smallest harness I could find).

We can't use a shoulder belt because the carrier needs to go in the middle of the back seat and neither of our vehicles are new enough to have a shoulder belt in the middle seat. Our human children currently occupy the seats that have shoulder belts.

Is there even a carrier out there that fits this requirement?