I got an '05 WR450, and was thinking about a magnetic oil drain bolt. From the posts I read when searching, seems people get little or no metal stuck to the magnet when they change the oil. Is this because the oil passes through the filter before it goes past the magnet? Would it be better to get one for the sump or for the frame? Or both? Maybe an oil flow diagram might help, if anyone can point me in the right direction.