Hi Flare:
1. An Electric motor is a propulsion device, not the transmission in the Prius I and II’s application.
4. Protrusion into the front passenger compartment then. I thought I had read of the actual volume with the rear seats folded down but I don’t have a value listed in my Hybrid miscellaneous fact sheets

Toyota and the EPA only list passenger and luggage. If I come across it, I will let you know.
5. Follow the links from both Toyota for the 2005 and Edmunds for the 2004 as provided.
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___
Waynegerdes@earthlink.net