I have an altura stainless steel tailgate rack, on all the time,similar to the vw rack
2 bikes – easy – 40 seconds, 3 bikes – 2 mins, 4 bikes – tricky so stick one in the back and put three on the rack, we put 4 on the rack when needed but means swining the bars and removing the seatposts etc.
we need to let some air out for downhill tyres.