Just to expand on the above post, you really do have to slacken the knobs. Realistically? 15 seconds plus x 2 knobs, so not "quick release"... and the upright bar might not tilt forward enough anyway, if the base is loaded with bikes/box/bag etc.
For the above two pics (The Easy Base), I'd have to remove the bag/bikes to be able to fold the bar down and fully open the tailgate.
What you need, is something like this...
... Which I believe is the Thule Euro something or other (Sorry, I bought it second hand, off a mate!)
EDIT:
Just realised, that latter pic is of course, just a cycle carrier. No good for luggage box/bag/basket, unlike the Easy Base, which can be set up to carry any of them.
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