How do they fit so many cars on Condor ferries? eg. type which go between Poole and St Malo

Yes I have asked this question before and was obviously not taken seriously. Answers included KY jelly, JML vaccuum bags and tardis type answers. Very funny and thanks but I really want to know facts and figures about how this is done. How many are on each level? Do the ramps move up and down. What is the actual headroom from the base of the boat (inbetween the two hulls) up to the ceiling below the cabin area? Serious answers only this time, seriously.