Windshield replacement
 

Another data point for those deciding on replacement windshield glass.

2007 X3 3.0si, original glass. Rain sensor. Lots of small rock chips, none worth going to the trouble of replacing the windshield for. Got a larger rock chip that spread into driver's line of site a month back. Windshield deductible is $200, but you play by the insurance company's rules. In my case, that is ICBC, a quasi-government organization. My local glass shop (national chain) is 1 km away, and could get it in the same day I called. They deal directly with our provincial insurance provider, I don't have to go to a claim centre. I asked about the rain sensor issues, and they advised that they use a variety of glass suppliers, all the options they would draw from were special windshields with the rain sensor already attached, no attachment of the sensor required during install.

Glass was replaced, saw it was PPG on completion. Known brand, not an issue.

It wasn't raining then. Two days later when it was, the rain sensor was unresponsive although the wipers worked fine otherwise. Over the next few days it occasionally wiped with the sensor, and once went to full on. They looked at the sensor, couldn't see a problem with it, and ordered another windshield. They wanted to wait two weeks from install date for the glue to fully cure so that they could cut it out more neatly, they said it can make a mess being 5 days old. OK. They were going for a different supplier. They called after it was installed, no joy. They could get a third windshield that afternoon, I didn't need the vehicle so left it with them another day.

Picked it up today, it looks good, and they advise they tested it. They also brought staff in from their head office to review the repair (I met them when I dropped it off). I will have to wait for rain to see how it is, but I am hopeful.

But I do notice it has a BMW roundel in the bottom corner, so on the third try they went with the BMW product. Interesting.

Might have been an issue with the sensor connection during install. Not sure you can just "look" at a sensor to see whether there is a problem with it.

Two years ago I replaced the windshield on my E46 with one from PGW (spin off automotive arm of PPG). I've had no issues with it. Once in a while I get a mysterious dry wipe which is always fixed by turning it off and back on again. It's never failed to work when it was wet.

Insurance companies love to lowball on product replacement and I love to fight with them about it.
So far with the printed information from this site i've managed to argue a good case. JCL's post is
just another resource for all of us to use as proof that windshields need to meet MFG's specs or better yet OEM.

When I took it back the first time they checked the connections. No issue. They inspected the sensor, but couldn't see anything wrong with it. They ordered another windshield. Then did all that again. Then installed OE glass.

It may have been a bad batch of windshields or sensors. They suspected that my system was more sensitive to the sensor signal than usual, but took full responsibility in any case.

Interesting.

I had the PGW comfort glass windscreen put in my X this summer, and the rain sensor had worked flawlessly since.

As you already pointed out though, the rain sensor should already come attached to the replacement glass....best to make sure that this is the case as some companies WILL order the wrong glass and try to re-use the old sensor.

Windshields are made by 2 or 3 companies worldwide. Then they put whatever logo on it to be OEM and the price goes up.

I installed already 2 windshields with light sensors - no BMW logo on them and they work perfect. One on my e39 the other on my e53. The e53 had when I purchased it, the auto lights didn't work. Checked it and the cutout for the light sensor was blocked off with dark paint (same stuff that is on the edge of the windshield. The windshield was perfect, but I changed it to have the auto lights & rainsensing wipers work.
You still have to recalibrate the element with GT1/INPA after the install. No issues.

Maybe the first couple times they installed the windshield with the blocked out window - it's hard to see, because it's behind the rear view mirror and with or without the sensor you have to look really hard to spot the cutout for the sensor.

The problem was the rain sensor, and the two windshields that didn't work were inspected by the glass shop. They brought in senior techs from another location. They said there was nothing apparently wrong with the glass or sensor, but agreed it didn't work. They said they had used that aftermarket glass with installed sensor many times and were confident in it. For the third windshield, they went OEM. Worked perfectly. They suspect a bad batch of windshields from the aftermarket supplier.

You are incorrect that parts made by an OEM are necessarily the same for what they supply to a manufacturer to be sold as OE. They may be, but they are not necessarily the same. I worked for a Tier 1 supplier to the automotive industry, and in a separate distributor that sold OE parts. Lots of differences are possible, including quality, testing, and subcomponents used. Sometimes a subcomponent is proprietary, so they put a substitute in that may or may not work the same. Things that relate to the PPAP certification can also cause changes when a non PPAP part is sold directly. Saying that the component is identical except it has a roundel is like saying that another brand of car becomes a BMW if you put a roundel on the trunk.