I don't think that data is meaningful. First of all, the link is comparing 2008 "Brand Value" with 2007, which I assume means how much a company is worth or how much they sell, not how good they are or how they have changed over 10 years. If you look at the link for 2001, you see the "brand values as follows:
Brand 2008 value $m 2001 value $m
Toyota 34,050 18,578
Mercedes 25,557 21,728
BMW 23,298 13,858
Honda 19,079 14,638
Ford 7,896 30,092
VW 7,047 7,338
Porsche 4,603 n/a
So the biggest growers, no surprise, are Toyota and Honda. And the biggest loser by far is Ford (although I don't know why GM wasn't in the list). BMW grew a LOT more than Mercedes.
Is there anyone who can really argue that MB put out good reliable cars in the past 10 years??? I think they have been fantastic but only slightly better than Jaguar for reliability. People who want reliable cars don't buy them from Germany. MB's glory days are in the Pagoda days, not in the present.