Well that was annoying, went to change the oil. Got er up, put on the appropriate socket and..... stripped the bolt head into a nice useless chunk of Chinesium.
Pretty sh**e quality metal me thinks, but I mostly gotta blame the dude before me for cranking it down too tight. Got it off with some channel locks and a torch. Bolts ruined of course but another is on it's way and shall be here Sunday.
But let it be a lesson to be learned: know your strength and don't use it on your drain bolts!