Thule Cargo Carrier

I've been thinking about prepping for a long trip. Once issue is storing dirty laundry so as not to stink up the car. My idea is some sort of cargo box on top of the car, like a Thule Cargo Carrier. Another option is to carry a hitch mounted trunk. These probably reduce wind resistance, compared to a Thule Roof Mounted Carrier, which increases wind resistance, lowering fuel economy one or two mpg. The hitch mounted carriers are really just platforms so I would still need a waterproof box to hold whatever I wanted to store in there--those would prevent opening the rear hatch--I don't like that idea much at all. I really like the Thule carriers because they open from both sides, and if properly secured, they will not let any water in, and don't interfer with opening the rear hatch door. I used one on a trip to Florida and we kept the inside of the car nearly empty so that the rear seat could be folded down for two teens to sleep while we were driving. The storage capacity was amazing, and the weight on top didn't seem to effect handling all that much, because the weight was centered and we had a good, tight suspension.

I discovered that Thule makes a swing away hitch mounted cargo carrier (left). This makes a bit more sense, since you can still open the hatch. Another issue is mounting a license plate to it. I have not mounted my front plate. Connecticut requires a front plate but they have gone back and forth so many times between requiring one and not requiring one, that I am not concerned. No Judge would convict me of this traffic violation given the inconsistency of the law. So, this carrier adds weight farther back, but should not impact fuel economy, except for the weight penalty.
Thule does make a swing away carrier that fits in a 1.5" hitch receiver--which is what I have. It is like having a second trunk and includes lights and a license plate mount.

As I am single now, on road trips, it will be just me and the dog, more than likely, so I can store things inside using a waterproof, odor proof sailing bag--which won't allow things to dry out, but will contain the odor of smelly clothes until I can wash them. I may need all that space in the back if I find a partner that likes car camping. There is room for two people to sleep in a pinch, if there is nothing else back there. So I am leaning towards getting a Thule roof top Cargo Carrier since I already have load bars. These come in silver which would match the car well. The Carrier to the right, is both aerodynamic and stylist...list price $810.

Some of the Thule carriers are very wide. That might limit my options putting a kayak on the roof. Wider load bars might fix that. The final issue is all of these things need a place to be stored when not in use.