I'll post pics later but if you're not fussed about the blind spot then call Walkinshaws - they have heated mirror class in stock

You'll still have to run the cabling which is a PITA as my elements are rated at 15W and I had the indicator cable to run too.

I found a tap for the heated rear window in the drivers footwell, so connecting them to that relay was fairly straight forward

And Stef - 60 degrees for 10 minutes in the oven...you know what I'm talking about - and instant success.