Engine pre-heaters are as rare as hen's teeth here in the UK. You can get them but they're really expensive, and there is approximately one manufacturer and one model of heater to choose from. I can get them from the US but they are mostly 110v, and also there can be import tax problems when buying stuff from the US.
But today I found a company in Germany...
AutoteileOst (look for 'motorvorwärmer')
...who sell a range of cheap engine pre-heaters. There is a bit of a language barrier but I think I have found my supplier. UK cars almost never have engine pre-heaters fitted, but I guess winters in Eastern Germany are a bit colder.
Has anyone had any experience with Autoteile Ost?