Last year I had problems with a German company I was trying to buy something from, many e-mails and letters got no results; they even refused to give me the name of their Managing Director which they are obliged to do when requested.
However after doing some digging on the interweb I contacted my local Trading Standards Department explained the situation and the next call was from a nice young lady in the German Trading Standards, she was very helpfull gave me all the information I needed and offered to intervene on my behalf with the German company.
The EU has got it's act together & you can now persue companies across state lines.
For those who might be on their second or third screen, any warranty applies from the date of the new screen i.e. you can be coming to the end of the vehicle warranty but the screen warranty starts from the date the new screen was installed.
The only problem is deciding if it is a manufacturing fault or just a stone chip. Again your local Trading Standards will be able to put you in contact with a qualified automotive engineering consultant who will be present when the screen is dismantled and will write a suitable report, for a small fee of course.