The 95 S320 has the 104.994 engine.
The 95 E320 has the 104.992 engine (my car).
My car had the engine wiring harness problem.
I'm pretty sure that all 104 engines have that problem

If you have a chance to check the car, lift the hood and check the underhood wiring under the looms. Look at the electrical insulation of the wires. It'll be obvious if it has the dreaded brittle insulation problem. This problem doesn't hide itself very well. Plus, I would expect the owner to know if the engine wiring harness was replaced. He'd point it out as a selling point.

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95 E320 Cabriolet, 169K