Thanks for the reply. I think I'll save up my pennies for the Beru plug wires.
BYW, I replaced the distributor cap and rotor this weekend on my 560SEL (99700 miles). Old cap must have been welded on -- two of the 3 screws had to be soaked in Liquid Wrench for 30 minutes before they'd loosen, and the third was had to be broken loose by the local dealer's mechanic. It was on so tight, the plastic housing was completely cracked off around the screw. No way to tell it was the original or not. The contacts on the rotor and cap were so cruddy and eroded, I'm surprised it got 20mpg on the road. The idle has cleaned up really well -- I expect more when I add the new plugs and plug wires.
This forum has been great. I hope I get the chance to repay the wonderful advice I've gotten here.
1989 190E 2.6