As one whose motoring seems to consume many screens
, I have discovered that my Mini dealership actually use a local mobile specialist for new glass. It's the same company for the Peugeot dealer and the local Ford dealer!
For my previous Peugeot, my son's Saxo and my Ford van, the local guy charged only a few Pounds more than my excess (and less than half the price of a national chain). The last Mini one was an accident repair, so Mini did it, but my Cooper has a great crack and chip, so it will need one soon... I'll go to my local specialist (A&B Windscreens of Andover) who will offer me a choice of glas, I'm sure.