I promised multispoke this info, but if anyone is also interested I measured the rear legroom with the sabelts. Measuring across the flat of the rear seat bolster from the back to where the tape touched the sabelts it is:-
Fully forward 27 inches
Fully back 21 inches
Don't know whether this is different from standard/leather seats
Fully forward 27 inches
Fully back 21 inches
Don't know whether this is different from standard/leather seats