Since the X2 doesn't have roof racks for the US market, I started looking for a receiver hitch. I found the Stealth Hitch and I'm very happy with it.
This hitch took me a while to install, requiring a cut through the heat shield behind the bumper cover, but I'm very happy with the hitch. Very little movement.
Unfortunately due to the design of the X2, the stealth hitch has to be permanently installed like a normal receiver. Cutting away the heat shield to provide enough space to manipulate the controls would compromise the support for the bumper cover and kick sensors. This isn't really a limitation of the Stealth Hitch, but an issue with how tightly packed everything is behind the X2's bumper cover.
It took me about 5 hours to install by myself, without lifting the vehicle. The installation documentation is pretty spot on, other than missing a note about cutting the heat shield. I had an issue with the wheel arch trim separating on removal, but some super glue fixed that.
5/5 I'll probably be throwing one of these on my Subaru, install looks even easier for that.