The scene this am:
Is there any official (BMW) guidance on when not to lower the hood in low temperatures?
In my Alfa Spider days, word was not to even touch the rear screen when it was frosty and not to lower the hood (the rear screen also folds on those) when the temperature was below 10degC. The screens seemed particularly prone to cracking. Neither was there a zip-out replacement option. Someone had come up with a two-piece glass conversion- I've not seen similar for the Z3.