I am about to replace the rubber piece on the wiper blade too. Strangely, the wiper blade is (25 inches) long on the 99 E430. I couldn't find a replacement refill or the whole blade anywhere, but the dealer. I believe the rubber piece is the Bosch Micro Edge Excel version. The rubber is completely wrap around the metal piece.
I don't understand why Bosch would make such an odd length, so that it doesn't even sell the refill in a regular auto store.

Car Nut
99 E430 Sport