I need to carry my Ocean Kayak which is quite heavy as well as an occasional roof box. From past experience on other estates with rails it's easier to whizz on a couple of lockable Thule cross bars. On my Legnum I keep the bars on all the time in the summer. I had removable Thule pads and rails on my 156 saloon but they started to bite into the rubber after a while - is it the same style of fit on the 159 saloon or sportwagon where there is a lug under the rubber above the door?
Aesthetically I prefer the permanent roof rails on the 159 SW as it makes the car look better, more purposeful!