I've just traded my Mk5 golf in for a new Leon and had the same problem. Was promised rubber mats as part of the deal, but Seat Uk don't have them. I had some VW rubber mats in my Golf, which i took out. They fit perfect, but have Golf written on the drivers side.
i went to vw and got some rubber mats..perfect!
Simon - you dont happen to know if the rear mats are the same shape as the mk5's do u? i could do with some rubber ones in the back as well u see
g