If your QX30 didn't come with a power lift gate, I'm not too sure how easy it would be to install one. You can always contact the dealer and get the part numbers or whatever and I'm sure they'd be able to order it in.
I believe none of the QX30 comes with the power lift gate! Mine are the Premium with technology packages with 19 inch wheels and didn't come with the power lift gate....
If some have one, please let me know to look for the part ##
That video is of a Q30, not a QX30. That's also in Asia somewhere, probably China. None of the QX30's come with a power liftgate. Though, the GLA 250 does have a power liftgate as well as the Q30 in that video (which has the box in the trunk, making it seem like there might be a kit out there).