Here is another supplier of covers I found a while ago, they look to be reasonable quality:

http://www.autosportcatalog.com/index.cfm?fa=p&pid=1793&cid=9

Then, there are these (this looks like the one you found on ebay):

http://www.performanceproducts4benz.com/productpage.aspx?cid=2&sid=173&pid=106904