Maryland Commercial Law Section 14-1003

      (a)      An automotive repair facility shall prepare an invoice which describes:

            (1)      All work done by it, including all warranty work; and

            (2)      All parts supplied by it.

      (b)      The invoice shall state clearly if any used, rebuilt, or reconditioned parts have been supplied or if a part of a component system supplied is composed of used, rebuilt, or reconditioned parts.

      (c)      After the customer signs the invoice, the automotive repair facility shall give him a copy of it and retain a copy.