I've seen two people on this thread so far talk about problems locating the relay. I have a USA spec c280 1999 with no heated seats.

The relay is not under the plastic cover as illustrated in the original post, but two people on this thread mentioned similar trouble finding it, but they didn't mention where they finally found it! My dealership has tried their best to help but after 1/2 hour they gave up too.

I need to find the alternate location for this relay - can anyone help?