After years of looking for a Canadian source for clear corners for my 'ol 16V, I gave up in frustration. Shortly after buying my C230, I searched once again, finding nothing.
Some of our local "ricey" shops carry them for Honda, etc, but will only special order for MB, and the units they carry are VERY low quality, and I wouldn't bother installing them.
For us Canadians, we're stuck buying some parts from the US at very high cost.