XA-XD commercials were far worst for rust than HQ-WB. That (and the way the Holden was constructed) is the reason why there is so many more Holden commercials left today. The XA-XD commercials rusted out in the sills/floors very early in life and it was structural hence they were taken off the road and wrecked/scrapped - or they were used in demolition derbies as they are a monocoque construction (and got flattended by HR-HG's). Normal rust in a HQ-WB commercial is superficial and easily repaired ie cowls and floors. Or the cars were easily rebodied in half a day with a few mates - there used to be heaps of tradies utes around local to me even less than 10 years ago with mismatching panels and colours. All that era Fords were gone as trade vehicles by the 90's. I'm not sure what Ford did by the time XF came around as they seemed to have lasted better yet they are identical construction. Maybe zinc coated steel like the 62 series 'cruisers?
I remember my cousin buying an XC ute in the very early 80's, it was only 3-4 years old and had been all its life in Tamworth area. It had bad rust in the sills even then, rest of the car was schmick.

I have always maintained the XA-XC rusted way worse than the HQ-HZ and thats why there were so few on the road by the mid nineties, but that was with my motor mates in the Holden versus Ford days, and its just too harsh to do Holden vesus Ford now! (no lol).

I reckon XY was actually better for rust, they seemed to outlast XA and XB. The XA sedan had really cool taillights, but its so long since I've seen one on the road, and that XC dash with the deep inset guages was shark like alluring, matched the body style well. But I agree with HK, in my opinion the XA-XC Fords rusted quicker, and it seemed to spring up all over... Maybe it was even just the topcoat paint they used, and not the design shape? Had Ford changed its paint factory by XF? True, the Falcon coupes are staunch as, I'd have gone deep grey with a heap of clear over the top, or even the purple, or the yellow and black if I was gonna ever own one, but for me it was always Holden.... the Tory was lighter to push than an XC coupe.