Issue #2 - Roof rack for A4 Avant

[ricematthews]

I am looking at purchasing a roof rack for the A4 Avant (i.e.:  one that
mounts onto the standard factory bars).  Are the factory racks worthwhile?
Who makes them for Audi?  Any preferences between Yakima vs. Thule?  The
fitments came down to the Yakima "DoubleCross" or "LowRider" or the Thule
"415 Railing Foot" or "751 Rapid Railing Carrier".  Do any Avant owners out
there have experience with accessory racks?

Thanks!

-Mark