I am also a bit confused. My A54 is number 68 from 2007 with a ZF25-2.0 gearbox, serial number 156 44 8. I believe the dipstick when I bought the boat 2 months ago is too long, measuring 128 and 140 mm from mating surface to high and low marks. I bought a 3311-301-003 from the Ft. Lauderdale dealer, but it measures 102 and 114 from the mating surface to the high and low marks, which is longer than you stated. I don't know if I should just put in 3 litres and mark that on the dipstick as a reference point. Any suggestions? I emailed ZF, but have not had a reply.