I replaced mine two days ago, and it took 45 minutes for both windows on my 300CD. It was cracked and split on my car, but it wasn't that bad. I think the weather stripping installs slightly different on a CD though.

I bought my weather stripping from PartsShop, and they were $13 each, but they cost more on a coupe. I still need to replace the inside stripping, and they are $20 each.