Whatever you do, don't use J-B Weld. My Saab 9-3 came with a glued sump plug. The stuff is permanent, even on oily alloy.
We had to weld a bit of steel to the plug (it got hot) drag it out and then weld up the cracked alloy sump. This was done in place and amazingly never leaked in 150,000 miles and 15 oil changes.
I'm currently driving the last of the 9-5s and dreading changing to some SUV identi-box
How many Airheads do I see on UK roads? Not many. 9-5s? None. 9-3s? at the weekend very occasionally. Identical SUVs with brain dead motorcycle-unaware drivers (like dead people) "all the time"