You can pull out of the deal if you want to for this reason: www.honestjohn.co.uk/faq/damage/ It will probably be okay, but fitting a new screen is very invasive. There could be leaks and there could be rust due to the screen frame having been scratched. If a big national glass-fitter fits it, then it might not be original manufacturer quality screen. And if there are cameras and light and rain sensors behind it they might not work.