The Wing mirror glass fitted to BMW's is prone to failing. Water gets in behind the glass and makes the mirror go cloudy with Brown spots appearing. This normally shows itself down the vertical line separating the standard part of the mirror and the wide-angle part at the edge. This doesn't look particularly attractive and eventually starts to hinder your vision in the mirror as it spreads. The standard glass is heated and has an 'anti-dazzle' blue tint. Replacement glass from BMW is good quality but will still fail again over time. It is also very expensive indeed. I can offer you a much cheaper alternative. The replacement glass I offer is not made by BMW, but still made to a very high standard and at a fraction of the price. It has the heated element built in with connectors for the heater wires, just like your original . It also has the same anti-dazzle blue tint. It is a straight swap for your original glass and looks nearly identical. The vertical line separating the main part of the mirror and the wide angle part at the edge is very slightly different in appearance. It is a very minor difference that most people wouldn't even notice. This is the reason I only sell the glass in pairs. It makes sense to change in pairs anyway, as once one side goes, you can nearly always guarantee the other side will follow. It only takes two minutes to change and enhances the appearance and safety of your car. It is very easy to fit once you get your old glass off. It just pushes/clips on. My glass also comes with genuine 3M branded double-sided sticky pads to secure the glass to the mirror base. This is not essential as the glass has it's own plastic backing plate that 'clips on' but the 3M double-sided pad gives you extra security and peace of mind. Cutters Special Forum members price only £35.00 per pair delivered. PLEASE NOTE that around 2005 BMW moved the position of the terminals for the heated element to the opposite side of the back of the glass (moved to the inside edge of the glass, closest to the car). Aftermarket mirrors like the ones I sell also moved the position inline with BMW. What this means for anyone with an earlier M3 (approx) pre-2005, your wires in the mirror that connect to the terminals for the heated glass will no longer reach. I have no idea why BMW did this, but to resolve the issue BMW now sell extension wires so you can still connect the heated glass. BMW sell these extension leads for £8 per side. I make my own wires up and only charge £10 for both sides. To see if you need these extension wires, please remove your wing mirror glass from the mirror housing. If the connectors on the back of your existing glass for the heated element is furthest away from the car then you will need the extension wires. If yours are closest to the car, then you will be ok. Any questions about this please ask.