In winter it is very handy to have heated mirrors. But there is no factory option for heated mirrors. Searching ebay I found some cheap heated mirrors for the C1, which have the right shape and come with new backing plates. To install you have to remove the existing mirror first. Not that easy on my car. Despite being carefull, only one mirror survived.

Next, remove the door panels. Not going to describe that again, see the installation of the automatic window setup.

Next, we need to remove the cover plate.

Slide it towards the front of the car to remove it.

Remove the two screws holding the remaining panel in place and pop it off.

Now remove the three bolts holding the mirror in place and support the mirror while doing this. You should now be able to remove the mirror.

Next we're going to run some wire. I put a straw between the controlstalk rubber, so it is a bit easier to put the wires through.

Now feed two wires through the hole.

Now we need to drill a hole in the inside of the mirror housing. Please take care to drill high enough! I drilled too low (twice), and lower in the pilar you will find the spring to fold the mirror. After drilling the hole put a guide wire through.

Connect the two wires to the guide wire with some tape.

And pull the wires through.

I choose to solder the wires to the mirror. You can also use connectors, but I don't think I'll be removing these often.

Next I put the backing plate in the mirror housing. It clips to the center piece.

Degrease the backingplate, remove the protection for the tape on the rear of the mirror and stick it in place.

Pull the wires through the mirror so the rubber cover flap can be put back in place.

Now feed the wire through the hole in the door.

Very carefully pull back the water covering. The black stuff is very sticky, take care of your fingers.

Now put the cable between the two door sides and pull it out at the water covering.

Now the mirror can be put back in place.

I disconnected the cable guide between the door and the car to get a bit more space.

Try and put a cable guide through from the inside of the car, through the cable guide to the inside of the door.

Connect the cables to the guide wire (there are 3 in the picture, I pulled an extra cable for extra window control).

After pulling the cable through the ground wire can be connected to the bolt near the door. Loosen the bolt.

Crimp a connector to the black wire and connect it to the bolt.

I guided the remaining positive wire behind the floorcover to the center console.

Then basically do everything for the other mirror :)

So in the end you have two wires that need a power feed. I looked at the location of the relay that powers the heater for the rear window, but it's not in a very convienient location (far under the dashboard). So I decided to take the easier route and put in an extra relay to power the mirrors. Not that the mirrors need that much power, testing on my lab powersupply suggests around 0.75A per mirror.

I connected two extra wires in parrallel from the rear window heater switch to control the relay.

And I connected those wires to the relay (pins 85 and 86). On pin 30 I connected a power feed and on pin 87 I connected both of the positive wires that go to the mirrors.

Seems to work like a charm. Pushing the button for the rear screen heater now powers both relays and the mirrors warm up nicely :)