There's a pretty bloody big difference between 160-170 degree temperatures and far higher underhood temperatures that cause the insulation to bake off the wires inside the harness bundles and inside the ETA.

Also, because MB spec'd an increasing use of "enviro-friendly" materials and "full" recyclability of raw materials (as we know they did in the early-mid 1990s, and which is reflected in many design choices in the cars, particularly post-W124) when the car's life ended, it seems that such corporate mandates would apply to the entire vehicle, not just the wiring bundles. So while individual departments and design/manufacturing teams certainly made choices in materials and costs, they also were all operating under the same corporate mandate to optimize their decisions for recyclability and environmental responsibility.

My point was simply that there's no definitive way to tell, and no way NOT to tell, without doing a thorough physical/chemical analysis of various wiring bundles throughout the car to compare. However, it seems odd (and illogical) to me that MB would ONLY specify "bad" wiring for the upper and lower engine-bay harnesses, and inside the ETA, while every other length of wire on the entire car is of the traditional type.

I guess there's no real way to know; it is what it is and harnesses need replacement when they need replacement. We feed the beast and move on.

Cheers,
Gerry