Steve - you're correct you don not need a promotional code when ordering parts online from Tischer. \You also do not need to be a CCA member to get the discount. Many retailers now avertising on other forum sites are giving 10 to 20 percent discounts.
Suggest you compare Husker Auto group (BMW Dealer) of Lincoln, Neb. They offer 25% off to all. Make sure you know what actual BMW list is before searching. Many (most) dealers charge 10-20% above actual list BEFORE offering discounts, etc.. Call several dealers and you will get several different prices on same parts at their "list prices"....
I just went to my local BMW dealership and showed them the price Husker Auto had the part listed for and my local dealership was willing to price match to the price I'd pay for the part and shipping from Husker. Ended up saving over 30% from the original price quoted by the local dealership. Husker has great prices so its worth a try.