At the bottom of my email order confirmation...
It looks like it might be a "special" number code,
but if it will help out someone good luck
To show our appreciation, we would like to present you with an offer code to receive 10% off your next order. Simply put
dw5370310 in the "Offer Code" box during checkout. Your discount will automatically be applied to your order! Offer must be used within 30 days. Cannot be combined with any other offer. Offer excludes Tires.