The first link is now a dead-end (at least when I tried a minute ago). As for the second link, it takes a while to download. For those who want to know the essential, here it is:
Outside the US market DAG [Daimler AG] offers the smart 4X2 in a micro-hybrid drive version (MHD). The MHD has significant differences to the US version smart including a special stop-start generator which requiers a wider V-belt. DAG has found that under certain driving and weather conditions MHS's wider generator belt may contact the plastic filler neck assembly and cause damage. This situation cannot occur in the US
due to the fact that the smart 4X2 is not sold in the MHD version and the filler neck assembly is metal as opposed to plastic.