Cargo roof rack?

Ok guys, I have another child on the way and with this addition we will max out our seating capacity of the wagon.
A couple times a year we head up North to cooler climate, and always tend to take too much with us.

I did a quick search on roof top carriers, and roof top bags, and found one thread on the matter.
I was wandering what you guys think would be better.
A roof top basket, with a bag?
http://www.walmart.com/ip/62.5-Roof-Luggage-Cargo-Storage-Rack-with-Fairing/29303415?action=product_interest&action_type=title&placement_id=irs_top&strategy=PWVUB&visitor_id=BMezl9ERrkHZNuHsS7o66U&category=&client_guid=4bfaed01-e2ef-45dc-835a-2995b951540a&customer_id_enc=&config_id=2&parent_item_id=23578516&guid=553eb0cd-7346-4b98-ac98-37df778c3e9b&bucket_id=irsbucketdefault&beacon_version=1.0.0&findingMethod=p13n
A roof top cargo carrier?

My concern was with the ease of taking it on and off, and storage when not in use.
I am not worried so much about the gas mileage, but the noise level either would create. I HATE pops, squeeles, whistles and squeeks when I drive!

Looking for advice from those who may have purchased something similar to these items.

You will probably have a lot more wind noise with the rack. The enclosed units are not all that heavy to move, and since it is probably plastic or fiberglass it will not be as prone to rust, although the plastic will deteriorate in intense sunlight. The enclosed unit will protect your stuff from rain a lot better.

I live in Arizona so the rust doesnt really concern me, but the plastic getting hard and cracking does.

One of my other concerns was storage. Some of the racks I found were no more than 6" in height. Some of the cargo boxes looked to be nearly 2-2 1/2 feet tall.

I will continue to look around. This may just boil down to cost...if my wife has anything to say.

Thanks for the input.

I have one of the plastic boxes. Although I have not used it for years, it did get regular workouts when all the kids lived at home. The one I have uses nylon straps and hooks to secure it to the roof rack track so it is fairly easy to install and remove at will. I have seen others that secure to the racks themselves with u-bolts right through the bottom of the cargo box. They are more secure, but need some time and a stepladder to install/remove. Mine hinges on one side with locks on the other so it is pretty easy to load and unload too.

It's not particularly aerodynamic, but I never noticed (or at least, don't remember) any noise from it. Of course, whenever it was in use, I had a car full of kids...

Thule makes a couple of nice aerodynamic looking models that feature a quick-release u-bolt system they call "Easy snap". They claim it will fit most factory roof racks. I have no personal experience with them, but would certainly be looking close if I was in the market today.

My brother had one that hinged at the rear and was a PITA to load/unload, especially on his taller mini-van. It did not have a lock, just a latch. The latch popped open one day, the wind ripped off the cover and they all had a 3 hour ride home with their recovered belongings piled on their laps.

I would not rely on any of them to be completely waterproof. A heavy downpour at highway speeds will almost certainly allow some water entry somewhere. Canoe pack liners will protect your stuff though.

Another consideration: storage when not in use. I have mine stuffed up in the rafters of an out-building, but some people may not have enough room to store the thing. At least bags collapse when not in use.