Thanks guys for all the great feedback!!!! 2 more days of use and no further recurrence of the Zone. The car is scheduled for an oil change in the next couple of days and I'll will investigate along the lines generously suggested above. The car had a pretty detailed tune up at 60K – and while it included all the typical stuff, it didn’t include plug wires. Are new wires & caps implied as a likely solution?

Glmoy: I am familiar with Schmidt. He did the 60K tune up on this car. Unfortunately, I won’t be going back there. I'll share the reason privately if anyone wants to know why.

Thanks again!!!!!

__________________
...Tracy

'00 ML320 "Casper"
'92 400E "Stella"