Speaking of updates, the dealer is probably referring to the Baumuster (type), like 170.xxx to 171.xxx. Those are model type changes. There are updates to the model between the type changes. As an example, the SLK350 changed from a 171.456 to a 171.458 in MY2008. The SLK280 and SLK300 is the same type 171.454. I think thats a MBUSA model description issue.