New windscreen advice

[Sidewaze Samm]

So a mysterious crack has appeared near the bottom of the screen, for no obvious reason. It comes up vertically from the bottom for about 4" then turns 90deg to the near side for another 4" - which has now increased to about 9"

I've read on the forum several times about the need to use a BMW seal (or was it trim?). I assume the insurer's appointed repairer is Autoglass, but yet to check (£75 excess if I use them, or total payout of only £100 if I use someone else).

So, could someone tell me:
What is the BMW item I need to insist on? Part no? Better if I provide it?
Does this go fully around all sides of the screen?
Does the fitter need to remove the scuttle trim from around the wipers?
Is there anything that can be done by me beforehand, to make the fitting easier - ie reduce the chance of damage?
What is the most likely damage etc I should look out for during/after the fitting?
Should I go to a centre, or are the mobile units OK? (Do they cater for wet weather fitting?)
How long does it typically take?
And anything else I haven't thought of - you get the picture...

Only ever had one windscreen replaced before, and that was 30 years ago when it was badly chipped driving home from the bodyshop where they had just reshelled my car after a big bump

Cheers

EDIT - I knew I'd think of something else! There is a DAB antenna stuck to the inside of the screen - can this be removed/replaced? Reckon the insurer would pay for a new one?

 

[ben g]

What is the BMW item I need to insist on? Part no? Better if I provide it?

It's the black trim that goes around the top and both sides of the windscreen. No need for a genuine BMW one, but the genuine ones do look better in terms of fitment at the 2 corners.

I've had 5 windscreens fitted to my Z4 (I know, terrible luck) and 3 of those trim pieces were rubbish. The latest one is perfectly fine, however. Autoglass fitted it, so will most likely provide you with the same part.

Does this go fully around all sides of the screen?

No, only the top and both sides. It's simply a trim part to cover up the sealant used to bond the windscreen in. It's not a seal so serves no purpose, bar cosmetic.

Does the fitter need to remove the scuttle trim from around the wipers?

Yes. The windscreen goes quite far under the scuttle panel, so it's impossible to remove and refit a windscreen with it in place.

Is there anything that can be done by me beforehand, to make the fitting easier - ie reduce the chance of damage?

No, but make sure you thoroughly check both A pillars for stonechips and/or any damage, as it appears my latest windscreen fitter caught both my A pillars slightly.

What is the most likely damage etc I should look out for during/after the fitting?

A pillar marks, the top corners of the new trim piece (they can sit funny and/or break apart), scuttle panel can be damaged upon removal. Wipers can be refitted incorrectly, requiring removal and refitting again.

Should I go to a centre, or are the mobile units OK? (Do they cater for wet weather fitting?)

Mobile are fine but no good if it's raining.

How long does it typically take?

About an hour. You then need to leave it for 30 minutes before you can drive the car.

There is a very good chance that they'll turn up with the wrong windscreen, as there are approximately 25 different windscreen specifications for the E85/6 Z4. Twice they've brought me the coupe windscreen and it is immediately obvious to the fitter that the shape of the glass differs from the roadsters. This is annoying as they have to rebook you, but that's life I guess.