Is it likely to be possible, assuming I can score the relevant parts? I'm annoyed that they don't come with it in the UK. I reckon it'd improve fuel economy not just because the engine starts warmer but also because the engine has to run less in the first 5 mins to deliver cabin heat. I'm like to believe that as is the case for the EV switch, the software is already there to operate it, and I should be able to just wire up the pump and level switches in the flask. It would probably be worth finding the contacts and checking for a voltage after startup to see if it's going through the motions.