How do they fit so many cars on to the Condor cross channel ferries?

Question

I have looked at the number of decks and the number of cars on each one and am convinced that they are some kind of Tardis. The cars just keep rolling in.

Answer 1

one at a time

Answer 2

they use jml vacuum bags and suck all the air out.

this makes more room

Answer 3

Lots of KY Jelly ;)