I have a lot of older Thule attachments for the Thule square bars, I'd like to use on my Mini. The local Thule dealer isn't much use. Anyone know if there is a simple way, either DIY or with Thule parts, to attach Thule square bars to a factory Mini rack?

(my attachments are mostly old style for the square bar, that cannot be converted to go on a wider bar without major (welding!) modification, so it seems like figuring out a way to graft on the old square bars would be more useful than trying to convert each of the attachments.)