MB book time on changing the 500E upper wiring harness is 2.5 hours (just had it done @136K mile). 8 hours is way too long, and expensive, for any R&R of a wiring harness that's basically plug and chug!! I was going to do this myself but my aftermarket warranty footed the whole bill. Like Tim says...its not too hard to DIY should you choose to do so.
Dealers pay under $400 for the 500E upper harness here on the East Coast....seems reasonable for a part that's like a spinal cord to the car.
