New style silver cross bars

[xwing1124]

Hi,
I just purchased a set of O.E.M. crossbars (0507.3100.500/1) for the ML- the shape of the bars is a flattend oval 1 1/8" tall by 2 1/2" wide silver bar w/black ends and a T-slot for the parts that attatch to the bars, They look like the all black version were it mounts to the side rails , it also came with 4 peices of rubber striping to fill the slots when not in use to reduce wind noise .

My question is were else instead of MB can i find parts that fit this slot ?.

Thanks in advance : Barry