Roof Rack
I have a Yakima rack installed on my 2005 Mazda3. Because there are no rain gutters on the car, the towers and clips rest on painted surfaces and can scratch the finish if the rack moves. One way to mitigate this is to cut three-inch sleeves from a large bicycle inner tube and slip them over the clips that attach the towers to the roof. Then there is at least some rubber between the paint and the metal clips. The rack takes awhile to install the first time. After the first installation, it is easy to remove and re-install the rack; I've done it several times. You will need a wind fairing. Without it, the rack will howl when you exceed 45 mph. The racks aren't cheap. You can check prices and determine what you need to buy at REI.com.
The principal advantage of the Mazda factory rack is that the towers are inserted into pre-drilled holes in the roof structure. They do not rest on painted surfaces and will thus not scratch the car's paint. Having scratched my paint with the aftermarket racks, I'd buy the factory rack in a heartbeat. I don't think the price difference would be too terrible.