Well, I hope your experience when you get round to it is better than mine.
I moved onto the passenger side today, and initially decided not to remove the 4 screws that hold the surround trim in place. After much effort in getting the cover and plastic trim off I realised I would not be able to get sufficient access to paint all the areas that needed painting, even though this side was in much better condition.
My T10 bit didn't fit, which is when I realised that on this side they were held in place with philips, or more properly Pozidriive screws. This time I fed them diesel to begin with, followed by WD40 and a couple of hours to let it all settle in. With a decent driver, forcing pretty much all my weight on the head and using the other arm to gently apply increasing amounts of torque two of them yielded and came out in one piece. Two of them broke at the head as before.
So it would appear that not only have the original power parking mirrors been removed, but the replacement black ones came from two different cars.
Take a look at the picture below. The drivers mirror has been mounted slightly out of alignment, and I have no idea what has happened to the passenger mirror. It does have the correct electrical connectors in the right place on the back, so is this from a 9-3 or something else. The backing pates seem correct 30 495 / 30 496
When it comes to the painting, after progressing with the drivers side this morning, I think it's better to flat the existing paint down to the metal surface rather than use filler. You end up with a finish that is too smooth otherwise