I can see this being a problem... firstly is the Mk1/2 drip-rail at the front going to foul the feet of the front roof-bar? And then I guess the wood at the back will foul the feet of the rear bar too? The wood I can bear to deal with by routing-out a slot in it. But is the drip-rail going to be a showstopper at the front - I think it was omitted on later Minis?
I do need the rails to fit right at the extremes of the roof for stability reasons... have just sold my camper and I still want to go kayaking. Though if the Mini doesn't already turn enough heads, it certainly will when it's got a *16ft* bright red sea-kayak strapped to the roof. Drivers of 4X4's will look down from their elevated eyries to see a boat apparently flying along the road all by itself.
