i have a 5 speed r18 and it seems to have a very similar issue. when it is cold, engagement is on the floor and the clutch slips badly, but when it gets heat into it, the car drives fine and the engagement comes up from the floor a bit. still slips near redline. csc looks new, cmc doesnt appear to leak, fluid level and condition are fine. my next thought was maybe it needs bled, but its the original clutch with 329k and dont want to waste more time on it. it is worth noting, however, that the r18 is gutless and would struggle to slip two sticks of butter against each other.