I do not believe Dinan themselves offer any CCA discount, however they do have sales on occassion. I purchased my Stage II suspension from an authorized Dinan Dealer in February when Dinan offered 40% off. The authorized dealer, Mechanic Masters in Spokane Washington gave me a large CCA discount on the labor. The owner of Mechanic Masters is a CCA member and one of the best BMW mechanics I have known.
BMW CCA is going to raise it's dues in June I believe to $40.00 per year. If you save 10% on parts purchases, spending $400.00 in one year you will have saved your dues. I get up to 25% off at some places. If you own a BMW you should belong to BMW CCA.