Rob Hill's look good. I fear I'd leave them mounted forever for convenience sake.
I already bought the best full grain leather luggage ever all 3 sizes plus the duffel see here: http://www.saddlebackleather.com/categories/85-Suitcases/products/1659-Leather-Suitcase-Chestnut

The suitcase goes on the rack, but will I have sufficient space behind the seats? For some reasons I can't visualize my wife and a smile with the duffel bag on her lap as we drive past Dijon.