The LX4, LX6 RB4 and UFR models are apparently due for revision between now and S2 final, therefore the 2048 wireframe templates that the vast majority of high quality skins are made from are not available for those cars.
That being the case I doubt you will see many of the better known skinners regularly producing work for those cars anytime soon. The default LX4/6 skins don't carry very much detail at all, in fact they don't even mark the position of the bonnet vents, which just makes the sort of high detail precise skinning that you regularly see for the GTR cars much more difficult.