Don't know about aluminum on the benz, I have a C230 and it's steel as far as I can tell. The VW's are a lot more popular in the salvage yards, hence a better price.
Also picked up a Mr Lugnut, it's similar to the Gorilla Wrench someone else bought but at $9.99 at Walmart, it's a better deal than the guy on ebay that wants about $35 shipped. It telescopes to 21" so you get good leverage. I'll just put a 15mm socket on it and be done with it. Comes with a plastic pouch to store it in.
