on my 300se and my friends , both 5mm drain plugs were impossible to remove , both streped .used a brandnew craftsmen 5mm allen. I ended up having to remove the pan and grab the small allen with vise grips. my friend bought a new pan only because his had a dent on the side. the new pan also was difficult to remove the plug. I would think they would apply a little bit of never seize on the threads. Or maybe a plug that is not an allen. most drain plugs on other cars are bolts. Never had a problem with bolts. Is there an aftermarket plug? the problem with the 5mm allen , it that when it streps.you cannot remove it with vise grips from under the car because the tranny pan and drain plug is right next to the exhaust pipe making it impossible to grip.I changed the pan gasket and filter and put copper never seize on the threads.took about 7 qts.of Valvoline maxlife dextron II.I heard of removing the fluid thru the fill tube with a 12 volt suction pump.has anyone tried this? thanks