I am near Toronto, Canada. It can get really cold here. I put one of these on my 85 300TD. I am not that mechanical, but I found it easy to install. It smokes a bit the first time you use it each the winter, because I have the typical oil leaks. I gave me a bit of a scare until I figured out what it was

http://www.padheaters.com/index.html

I think it's the way to go.

Peter