I installed a block heater, took us about 45 minutes. I needed a friend with a skinny arm (I have popeye type forearms and I couldnt even get my arms up there) to position the block heater. I bought the block heater here on PriusChat and it works GREAT.
Well Ive always wanted to visit out west and all but my arms are too big to help with the install anyways
I have an 06, since new, and have 240,000 miles on it. Only real problem was a front wheel bearing starting squealing and I changed it. Everything else was routine maintenance. Enjoy.