My 98 E300 was picked up in Germany by PO and like all of these cars (I think) came with a block heater. My car has spent it's life in California, so the cap has never been removed for cord installation. I remember something about a coupon that came with the original papers for a free cord. I doubt getting a free cord is much of an option at this point. But for other info their have been some past post in this forum or tech forum that had good photo's, so I would just use the search function in both forums.

Paul
98 E300