M3 e46 Rear View Mirror

BMW E46 M3, BMW E39 M5 and CSL Oval Auto Dimming Auto Dim Rearview mirror

This listing is for a fully refurbished genuine BMW E46 M3, CSL & BMW E39 M5 auto-dim rearview mirror. This is the Oval rearview mirror fitted as standard in to the E46 M3, BMW E39 M5 and CSL. Before refurbishment, I start off with a genuine BMW oval rearview mirror. I carefully only select the best possible mirrors to refurbish. They are in excellent Grade-A cosmetic condition and have no physical damage. I also check that all the electronics are working correctly. It is hard to find mirrors in this condition but I have high standards. Most mirrors get rejected by me initially, due to damage. To meet my high standards they must be excellent. I then strip the mirror down and remove the auto-dim glass unit inside. There is an issue with the original auto-dim units where they will all fail sooner or later. This is due to a manufacturing issue. I re-fit one of my new improved auto-dim glass units. The mirror is then re-assembled and thoroughly tested before it is available for sale. This process then makes the mirror better than new. It will respond better than the original mirror and out-last the car. You also have the peace of mind that it will never leak out and damage your interior. This is something many of my customers have experienced with their mirrors containing the original (inferior) mirror glass.

For purchasing other shape mirrors please contact me. I keep many different mirror types in stock available for immediate delivery. I can also offer in-house repairs if you would like me to repair your faulty oval mirror. This is a much cheaper option for you. By appointment you can also visit me for repairs onsite while you wait. For repairs of your existing mirror or to buy the replacement glass for DIY figment to your mirror, please see my other Ebay listings***

You are most likely here reading this because you car is missing an oval rearview mirror or your current Oval rearview mirror has failed. If your mirror has failed, you may have experienced some of the following symptoms of your rearview mirror:

  • Mirror is no longer dimming
  • Mirror has a yellow tinge to it
  • There are patches or bubbles in the glass
  • Tide line or variations in colour
  • Dust behind the glass
  • Halo effect or inner circle present
  • Mirror has leaked. Damage to the mirror casing or interior trim

How an Auto-dimming mirror works:

An auto-dimming mirror is comprised of two pieces of glass that are sealed together along the edges and then metal contact strips attached to both edges.

An electronic circuit board is attached to the rear of the mirror with a wire soldered to teach of the contact strips.

A conductive liquid is then injected and completely fills the area between the two pieces of glass and then sealed at the injection point. The back of the glass is coated with a silver mirror coating and under normal (non dimming) conditions the fluid is completely invisible and transparent. It works just like a normal mirror should, reflecting all light. The mirror housing contains the electronic circuit board and photo-sensors that measure ambient light, one facing toward the front of the car and one facing out towards the rear window. The forward facing sensor tells the mirror whether it's day or night and enables or disables the auto dimming function accordingly. If a sufficient amount of light is hitting the forward facing sensor the mirror will conclude that it's daytime and will not dim the glass at all, regardless of what the rear facing sensor sees. When the front facing sensor see reduced levels of light the electronic circuit board will begin applying very low levels of voltage to each piece of glass and the conductive fluid will begin to darken. The level of tinting is varied almost infinitely depending on the conditions. At night the mirror will be dimmer than during the day, however, when the rear facing sensor detects light (from a cars headlights behind) the mirror will actually dim even darker. This effectively reduces the amount of light that hits the mirror coating and eliminates glare. You may also notice your mirror dims if you drive under tree covered roads or through a dark tunnel. The level of dimming is constantly adjusted depending on light conditions. Another neat trick, is that if you put your car in to reverse at night, the mirror automatically un-dims, so that you can see where you are going! It’s all rather clever really! 


Unfortunately there was an issue with manufacture of these original mirrors which causes them to fail. They will all fail sooner or later. It is more 'When' the mirror will fail rather than 'If' the mirror will fail. Due to the poor original design, when the mirror fails it can cause devastating permanent damage. There is a (dimming) fluid sandwiched between two pieces of glass and this liquid is highly corrosive. When the mirror fails it can allow this liquid to leak out. When it leaks out the glass it will eat its way through your mirror casing and then damage anything it drips on to. I have have had unlucky customers who have had centre consoles damaged, gear knobs, seats and even a dashboard. It all depends on what the fluid leaks on when it drips out the mirror. This can make it a very expensive failure indeed. Especially if you need a new mirror too. A new mirror from BMW is over £400 and still uses the same (flawed) technology as the original. Some customers look to buy another second hand mirror as a replacement, however these carry the same risks of failing as the original. It isn't worth the risk. Your best option is to repair your current mirror only replacing the part at fault, the dimming glass unit or (as in this auction) buy a complete refurbished unit with brand new (improved) auto-dim glass inside.

If your mirror has any of the above symptoms; the best thing you can do it remove it from your car straight away. Please bear in mind if you have a Convertible M3; by removing your rearview mirror some functions will stop working. You will no longer be able to lock your car with the remote fob. The central locking will no longer function and neither will the alarm. You can still lock the car manually using your key until the mirror is repaired and refitted in the car. If you have a Coupe, everything will still work as normal even with the mirror unplugged.

If you are buying this refurbished rearview mirror, you don't have to remove your mirror from your car until this one arrives. Then you can swap them straight over. As your mirror could leak at any time, it is often a good idea to place a towel underneath it and wrap it in paper towels. That way, if it does leak these should contain the spill.

The glass that I fit in to this mirror is the best available on the market today. It uses the latest, state of the art dimming technology. Rather than a liquid, my glass uses a special dimming 'Gel'. It is not corrosive and will not leak out like the original glass. It also dims quicker and goes slightly darker (when required). It really is far superior in every way to the original. It also gives you the peace of mind that it will not fail again and cause damage to the mirror housing or interior trim. The quality is infact so high and so superior to all other glass on the market that it is normally offered with a 3 Year Warranty on the glass only when customers buy it and DIY fit it to their own mirror*. I am offering this same THREE YEAR warranty on the whole mirror in this auction. This warranty covers any manufacturing defects with the auto-dim glass unit itself for three years from the date of purchase. As I have only picked the best possible mirror to refurbish for you, I have also extended this THREE YEAR warranty* to cover everything else in the mirror: sensors, alarm LED and circuit boards within the mirror. Consequential loss is not covered. The warranty is only on the whole mirror unit you are purchasing in this auction. The warranty covers manufacturing defects. I do not cover, accidental damage, water damage, damage from smoke or heat. For Reference, I have never had to replace one of these glass units under warranty and I have sold many many hundreds over the years I have been specialising in mirrors. However, if you do have an issue with the mirror during the three years, you will need to return the mirror to me. I will then strip down and ascertain the fault. I will replace the glass or any internals (if they have manufacturing defects). The customer is responsible for postage charges in both directions.

Buy the Best product on the market today from a passionate BMW M car specialist.

Any questions please ask; I am always happy to help.

e46 m3 auto dimming mirror
Price £235.00.

BMW E46 M3, BMW E39 M5 and CSL Oval Auto Dimming Rearview mirror

£235.00