I don't own a car, but I need to transport my bike(s) by car a couple of times a year. Since I can't predict what sort of car I'll have access to, I bought a
Saris Bones 3. I chose it for its versatility. It fits over many rear spoilers too. I've even successfully used it on cars that aren't in the
Saris fit guide. It also folds up and stores nicely.
As for the ease of installation issue, it all depends. It depends on the rack and the car, of course, but everyone also has their own definition of what "easy" means.
I find the Bones goes on easily. You adjust the legs for the car, attach and tighten three straps, then adjust the carrying arms. Some people I know think that's about as complicated as building a space shuttle.
Near as I can tell, "easy" depends on the person more than the rack.