I noticed a while ago that my sump was very rusty.
Over the last few days I've scraped, wire brushed, sanded and painted it.
Of course o e thing reveals another so decided to treat the front cross member at the same time.
Two of the bumper cover fixing screws sheared off despite my going carefully back and forth - I couldn't lubricate because go into the cross member.
So I sheared off the welded nut heated it and wound the remaining bolt back out. Nuts refixed with Plastic Padding - not yet tested in anger but I'm optimistic
I'm 'looking forward' to do a bit more rust treatment inside the wheel arch revealed when removing the liners!!
I've ordered a new full width undertray from Latvia so that should protect the sump etc.
Incidentally the fixing bolts for the undertray are 10mm diameter and just to make sure a 5kg tray doesn't fall off they are fine pitch (1.25mm v normal 1.5mm) for extra strength