i follow your problem reports closely as our cars are the same model year and approx mileage. you haven't had the harness changed right? from what i've learned i would pick the harness rather than the coils to be the culprit. i remember your saying you've had it since new so maybe you can get the dealer to do a goodwill replacement...
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"