Just thought that I would share my experiences towing this weekend. On Friday I purchased a small sailboat and transported if from Connecticut to Massachusetts - a total of about 220 miles all told. I installed a Draw-Tite hitch and the Camry wiring harness that I re-pinned using the instructions found here at Prius Chat - both were easy to install and worked perfectly. Total install time was 90 minutes or so. The boat and trailer weighed a total of about 750 lbs and the drive was mostly highway during a holiday weekend so traffic was fairly heavy. I stuck to the speed limit. My 09 had no issue with the trip - I was worried about both braking and acceleration and I had no issues with either - in fact over the trip I got a shade over 35 mpg.
Arrh dachshunds, that's what makes the difference. Their low center of gravity and aerodynamic shape.
Steve, you may already be aware, but there is a yahoo group called priustrailers that might be also interested in your experience. Here we may anticipate that you will be reminded that Toyota opposes this practice. Personally I wish that the Prius were better intrumented for all sorts of heavy work (MG temps, etc.) but things are as they are.
To play devil's advocate, if in amulti vehicle accident while towing with Prius, seems it might take judgement out of favor if 'they' state Prius is not approved for towing. Or could insurance even deny collision coverage in solo crash while towing? Maybe. Something to think about. I wouldn't tow with mine.
Wouldnt this denial have to be based on wither or not the trailer was, depending on your state, partially contributing to the accident? I would think so.