to come again to the usage of the rubbermats.

back in the days the rubbermats had been a 'penny article' and were given as an add on with the price negociation to throw sth in the ring. the actual usage was in wintertime, where you really needed these unless you wanted to have all the snow in the carpet, hence freezing, water stains, because of the salt etc on your carpet.
noone wanted to have these, so the rubbermats had been in the car.

the rubbermats where used on top of the carpet, as an extra layer and where taken off in spring time, when the weather turned nice again.

then either the extra mat, or the coco mat was trown in, summer usage to prevent the dirt, dust, whatever to spoil your original carpet.

the users of the porsche cars always had been premium customers and mostly they did pay respect to their investment and tried to keep the longlivety of interiour as good as possible.