Just click the "Anbieter kontaktieren" link and you will get a large message field on th right with three small txet fields on the left. The top one is for your name, the middleone is for your e-mail address, and the bottom one is for your phone number.
If I were you I´d send him a question and give my first name, e-mail address, and the click the "Anfrage senden" buttom.
Except if that would result in you buying a Pantera and selling your Longchamp, I´d recommend you to send him a kraut joke instead...