My mom has a 99 300e turbo diesel. It is awesome and has 86k+ miles on it. It was driven to Colorado and back to MA multiple times. I love to drive it in nebraska at 120+ mph speeds. The car loves the highway, and gets around 30 mph, less when i drive it
I don't know the production numbers, but i know that they didn't make too many of them. I am not sure, but I think many of the parts, minus the engine and some drivetrain parts, come from the 320e.