yes, left hand. If I'm not wrong, the leons 4x4 wasn't imported in the UK. infact awesome uk has nothing for the 4x4 version. please correct me if I'm wrong.
anyway leon 4x4 doesn't use a rear dif like torsen but use a clutch from the swedish haldex. it's not permanent. it works only when there is a slip between front and rear wheels. rear wheels can't turn faster than the front but on ice or wet condition, they could recive much torque than the front. this system works using the input signal from the ESP sensors.