Yes so do some of the 99 C class cars. I was really surprised when they handed me a flip key at the dealership for the test drive. One would think that the S class would have been the first car equipped with SmartKey. But since the w-140 was on the way out when it was introduced they probably wanted to wait for the new 220 body.

Honestly I prefer the flip key over the optical key anyway. The optical key seems kind of strange in my opinion.