4C Oil change

[993-4C]

Hi guys.

Did oil and filter change today. When removing the undertray I noticed that one of the torx bolts was missing but did not pay much attention. Once I drained oil and replaced filter and was going to get the tray back again I realized that the missing bolt was not actually missing; it had seized and had had its head chopped off (I guess during previous oil change). Then I tried to get the bolt remains out of the threaded bush but could not because the bush was rotating.
Was wondering what you guys think about not tightening back the bolts where the bushes are located (6 places) and just have the tray fixed with the remaining 8 bolts or anyway to make sure the bushes will not get loose. I mean I am not sure I could sleep well thinking one of those is going to seize next time I try to remove the tray.
On the other hand, has any body replaced this torx bolts with hex head ones that can be used with a normal socket?

Thanks

[StescoG66]

For a bolt I wouldn’t fret, but a bit of grease/copper slip on the ones you put back in is what I would be doing.

[993-4C]

Thanks for the tip. I don't have copper grease handy but do have graphite grease so will give it a try.
Cheers.