And now something, which I think no one thought of before: To prevent dirt, water and even salt water (from salt on the streets) (not that we have that issue in Australia) from entering at that newly trilled hole, I thought of something: After thightening all sump bolts (25Nm), I squashed black slicone thru that hole to cover it from the top and pressed a thin round bit of rubber underneath, pushed the big bolt back in, and then reused the now rounded and sprayed with clear coat head of the bold