The rubbers are what cost an arm and a leg!!
I want Chas to tell us how he fixes them for not much, apart from leaving them in a garage so they won't leak!!
I don't fix them, I stop them from getting worse!
My 1986 45S has a factory fitted tilt and slide sunroof. Amazingly as well, it has NO roof rot at all! The seal wasn't in brilliant condition but it did do its job. What I did though was to completely remove the sunroof, clean up and paint the whole mounting flange area first with zinc primer and then a good couple of coats of Smoothrite. The idea behind this was to seal and protect the area the seal would sit and help prevent rust from forming.
The seal I simply cleaned up as best I could. I removed all the old sealant from the seal's mounting channel and then gave the whole seal a damn good clean. I also soaked it in WD40 to try and re-vitalise the rubber somewhat. Then I refitted it with a good dose of silicone sealant to try and completely seal the area between the seal and the mounting flange.
I did that back in about 2004/ 5 and there's still no signs of rust! The sunroof still leaks a bit, mainly through the winder mechanism. I had all this apart and it doesn't look like it's protected very well from the water channels - a bit of a poor design. I have a suspicion they leaked from new!
As for costs, when I enquired a few years back the seal on its own worked out at nearly 50 pounds including VAT. As I'd only paid 46 pound for the car I objected to paying that! So yes, Rawill, they really do cost an arm and a leg. I have also managed to pick up a couple of complete spare sunroofs with seals that I'm holding on to in case anything breaks. The sunroofs and mechanism are totally unavailable new so that's why I grabbed them!
Note that the factory tilt and slide sunroofs fitted to the mk1's and early mk2's are different to the later mk2 sunroofs that only tilt. The later sunroofs have a tilt mechanism at the back, whereas the earlier sunroofs have a winder handle just in front of the rear view mirror. I like the having a sunroof, though it is noisier than the solid roofs as it never seems to seal completely and does tend to rust if not looked after. On those really hot summer days that we get a few days of every year they are a Godsend and help let all that heat out of the car. However, with Unos being so old they are a bit of a rust trap so many may wish to not have one.