Sales figures for the R-Class haven’t managed to live up to the expectations of the German luxury brand, but Mercedes Benz is determined not to completely write-off its ‘Grand Sport Tourer’ just yet. The R-Class received a mild facelift last year to help turnaround flagging sales, but a second and more extensive update is in fact planned for the 2010 model year as previewed by these latest spy shots of a prototype caught testing in Germany.

The first facelift came less than two years after the vehicle was first shown at 2005’s New York Auto Show, and was implemented mainly to increase the car’s desirability. A cheaper RWD model was added to the lineup as well as a more flexible seven-seater model, but other than that the car remained mostly unchanged.

For the next update Mercedes will give the car a major styling overhaul with a new front-end planned as well as a slightly revised rear and interior. Expected to be launched in the second half of next year, the new R-Class will likely receive the same squared-off treatment as the rest of the Mercedes lineup including angular headlights and a larger more prominent grille.