Steep discount on the Nashbar Shadow 2-Bike Hitch Rack
on sale for $130 plus $15 shipping (or go to local store in some areas).
I've owned this very rack for over 15 years and it is by far my favorite. What I like is that it holds the bikes by their wheels and a hook over the frame on top - super adjustable, super solid, and it works as well for my mountain bikes as it does my street bikes. No worry about the bikes banging together hanging from their frame. Wheels and forks don't flop around. Full suspension mountain bikes, no problem. Super secure and stable. Easy to lock your bikes up too to deter theft compared to strap mounted carriers. Works fine for little kids bikes too.
Downsides: You can pay double this to get a rack that folds. Even the two bike version above extends your vehicle, making parking a bit harder, plus it takes up a lot of room in the garage. The arms fold up, but not the part that goes into the hitch. It's heavy steel construction. Finally, the velcro straps around the wheels will disintegrate after a year or two. You don't really need them, but I use old fashioned toe straps (from toe clips) that Nashbar sells for a few bucks - very solid.
Here's a 4 bike version for $250 plus shipping
but not recommending. Will be too long and too unwieldy to store.
The Shadow Deluxe folds at the hitch which is nicer for $200 plus shipping ($50 more than the regular two bike Shadow). If money is no concern, then definitely
go for this version
And if you need 4 bikes, $300 plus shipping, and this one also folds at the hitch so it's not such a pain to leave attached to your car or SUV.
Final points - I GREATLY prefer to use hitch mount bike racks. They are much easier to use, don't scratch the paint on your vehicle, and are much more stable and secure. The ones that fold at the hitch are easier to live with attached to your vehicle and store more compactly in your garage or basement. I even added a hitch mount to my little Miata because it just works soooo much better than all those blasted straps.