<VV> Fasteners for a Roof Rack

[Ron]

A short while ago someone inquired about fasteners for a roof rack but I 
never saw any replies that went to the list, so, I'll ask again, can anyone 
recommend any particular fasteners for a chromed roof rack.  I assume they 
may be jack-nuts or well-nuts of some sort but what have been used with good 
results?  I'll appreciate any info.
RonH - working on a couple of wagons.