| I have the genuine Mini roof racks for 2009 my Clubman. I had the dealer fit them so I knew it would be done right, but I've since taken them off as I don't need them everyday.
The roof rack kit comes with little plastic plugs that fill the perforated slots when they're not fitted. Only takes about 5 min to install and remove once they have been initially fitted.
As for road noise, you do notice it but it's nothing too concerning and can be tolerated.
Funny enough, my wife said she likes the look of the Clubby with them on. They kind of work with the whole utilitarian vibe of the car and I'm fortunate they match my silver & black theme. | 
