I highly recommend you do this to be Pro-active as Preventitive maintenance before you actually get an issue with your glass. However if you are experiencing any of the following problems then you definitely need to act quickly: - Rear view mirror Not dimming - Mirror appears permanently dimmed or undimmed - Patches on the glass or areas of the glass a different colour to the rest - Bubbles appearing in the glass or one large bubble. - 'Tide marks' or lines in the glass - marks, bits or what looks like fluff behind the glass. The best most cost-effective option is to replace just the Glass inside your mirror with a brand new replacement ‘Cell’. This keeps the cost down as you are re-using your mirror housing, sensors, circuit board etc but just replacing the part actually at fault: the sealed dimming glass unit. This is where I can help you out. I supply Improved replacement Glass Cells that use a new technology that is a vast improvement over the original. Instead of using liquid between the two pieces of glass, a conductive Gel is used instead. It is also sealed in a different way to the original glass so it should not leak out again in the future. It still dims in the same way as the original glass. Some people have commented that it appears to dim/un-dim slightly quicker and go slightly darker when required. This is an improvement on the original and in effect makes it ‘better than new'. It should never fail again and gives you the peace of mind that your mirror is not going to explode at any moment dissolving your mirror housing, centre console, gear surround, gear gaitor etc! The cost of doing it this way is cheaper than even buying a second hand mirror. Bearing in mind that a second hand mirror could still fail at any point, this is a 'no-brainer' in my opinion! If you like taking things apart and can use a soldering iron, it is not tricky to fit this yourself. It takes minimal tools, just patience and care. I can do one of these in about 10 minutes now after fixing hundreds. If you take your time it will be about 30 minutes. I sell the replacement glass through my website but offer Discount to Cutters who buy it off me through the Forum. I have made up a guide to show you step by step fitting. You can find this on the forum or on my website: www.MirrorJohn.com Dont worry if you dont want to do this, I offer a full repair service on your mirror and even offer a 'Mirror Exchange'. I sell completely refurbished mirrors too. For a Limited time only I am offering these glass units for DIY fitment to all Forum members for only £90.00 delivered in the UK. I deliver 1st Class Recorded and can often send out on the day that you pay me. Worldwide delivery offered for additional cost. Please PM me for details.