Thanks demoncyclist. This is helpful.

I think not helping my situation is that with my electra townie the rear wheel really sticks up in the air like a sail and in my smaller car I can really feel it. I've tried a yakima adapter top tube bar like we use on my wife's bike, but it doesn't quite work.

I also once drug a trailer by the safety chains on the interstate (NOT due to the receiver breaking) and that was a scary situation that ended fine. So that is probably influencing my rational.