GOt the jack pad today, it was the $15 Mercedes jack pad part number 2039970186, infact here is the direct eBay link I bought it off of: Genuine Mercedes Benz Jack lift Pad rubber SLK280 SLK350 C230 C350 #2039970186 | eBay

While it was not an EXACT match, one can trim it to fit well, but for me, I just put it on the car without trimming and it pretty much went in and did the job. Totally worth saving that extra $50 for something with just a few corner differences.

So yes, it does work and function well, but it is also slightly different. Totally worth it.