I own a 95 850 (sportwagon), found a 95 850 turbo at my local junkyard, and bought a sweet (factory) rooftop carrier saturday for $13. saw that the donor car had welded nuts in the roof top channel. Easy, right, but my car has no welded nuts! It has two hard rubber block things (front, middle). No attachment points that I can see. Maybe there are tapped holes under the rubber blocks? any wisdom on this? Thanks!! Dave