[Daveycrewcut]

It is a good idea to have a picture of a windshield on your invoices so you can mark the type of break and location. That way if a warranty issue comes up, you will be able to tell if it was your work that failed or not.

You might want to require that a copy of the invoice be presented on any warranty work so you won't have to go through your copies. In that case, triplicate invoices would be handy. 2 copies to the customer (one for insurance and one for the glove box).