Has anyone found a way to mask the millions of tiny craters in the outer glass of the front windscreen in high mileage cars? They cause a multitude of reflections in bright sunlight to the extent that I've had to almost stop once or twice recently when I couldn't see the road. I have had three Octavias since 2002 and all of them have suffered with this problem, the only way I have found is to replace the screen somehow but with all the electronical gubbins linked to the vRS screen, my insurance company won't guarantee that a replacement will have the same connectivity.

i have the same problem with my 2000 BMW 740 which still has the original glass in it.....

There isn't a polish or film that reliably "masks" that kind of cratering. Once the outer surface is chewed up, light scatter in low sun is a glass problem, not a wipe or coating problem, so replacement is the real fix.

On the MOT side it is worth taking seriously. Manual section 3.2 fails damage in Zone A over 10 mm, or elsewhere in the swept area over 40 mm, when it significantly affects the driver's view. Zone A is the 290 mm strip centred on the steering wheel inside the wipe pattern. Dense pitting that makes you almost stop in bright sunlight is judged on that "significantly affects the view" test, even if no single crater is 10 mm. Excessive scratching that hurts swept-area visibility can also go Major or Dangerous under 3.2 (c).

For the vRS electronics: a proper ADAS-compatible screen for your VIN (right camera bracket, rain sensor, heating options per the PR codes) plus camera calibration after fit is what keeps Front Assist / Lane Assist working. Ask the glass fitter in writing that they will (1) supply glass matched to your options, (2) calibrate the forward camera with a suitable tool, and (3) confirm any radar alignment if your bumper pack needs it. That is the answer to the insurance "connectivity" worry, more than the brand of glass.

If you want a second opinion before you book it, ask an MOT tester to sit in the driver's seat in similar sun and say whether they would class the view as significantly affected under 3.2.

Are you sure it's external surface damage ? Modern windscreens are all tinted and the additives used to produce the tint seem to age and produce a light scattering effect (Oh for the days when simple clear glass was used - last time I had truly clear glass was a 2003 Astra). If this is the case then a new windscreen is the only answer.

If, however, it is actually fine external damage then it MAY be possible to polish it out. I have successfully polished out a couple of fine scratches (caused by an incompetent valet at a dealer saleroom) on the windscreen of a Golf using a felt wheel and cerium oxide with a Dremel type tool so I know polishing CAN work in some cases. In my case these were only localised scratches - not a whole windscreen ! And even then it was a laborious process. If you're convinced it's external then it could be worth asking a decent bodyshop or a windscreen specialist if they are able to sort it with a cerium oxide buffing. Like you I am reluctant to go for a replacement windscreen unless it can't be avoided - I've had a couple occasions over the years when the muppets have damaged the paintwork or the new windscreen has leaked.