.......that manufacturers applied a reasonably amount of grease to the end of any bolts involved in holding a spare wheel in place, as it's a seldom used item, and as such (especially given its position in the car) potentially reasonably likely to seize up, resulting in it snapping when you want to take the thing off.
On the Fiesta a while back, when I was down at the part worn tyres place getting a spare for it, the bolt holding up the spare wheel cradle was seized up, and when me and the guy there tried to loosen it, it snapped (I'd previously managed by just unhooking the hook, but for some reason that time the hook wanted lowering a bit. Ever since then the spare wheel's sat in the back of the van, and the spare wheel cradle (empty) has been held up with a cable tie.
On the Audi today I got a puncture, and pulled into the petrol station (conveniently located), pulled up the boot floor and all the other bits I need to to get to the spare, and it's held in by some sort of plastic device that looks like it rotates. Fair enough, this thing rotates - easy enough. Nope. It doesn't want to rotate. A couple of little plastic catches that look like they might release, but I try, and nope. Linger in petrol station until someone with an Audi comes in - nobody does, but I harrass some bloke with a newish Giolf estate - he doesn't know unless it rotates. Me a bit stuck. Put a load of air in the tyre (up to about 40psi) as the stone causing the punture is still in there, so it's not losing air super-quick, and get over to Chiswick (was on the A4, just west of the Hammersmith Flyover) and phone scoot for a tyre place in Chiswick. There's one just the other end of the high road, so pop in there, ask one of the guys there for a hand, he tells me it should rotate, and I ask him to come out with a hammer and chisel so we can destroy this plastic thing and get at the spare wheel. Eventually get the plastic thing off, and basically this plastic thing has got a hex shape in the middle that's supposed to grip on the bolt head to rotate it, but the bolt was too tight so it was just slipping. He tried to undo the bolt, but it was stiff, then it snapped (right at the end that screws into the bodywork), so I've got a lovely remainder of a bolt to drill out at the weekend.
But both of these instances wouldn't have happened if the manufacturers had put some grease on the end of the bolt to prevent it seizing up. I mean, let's look at the evidence - it's something that's (hopefully) quite seldom used, and it's situated right on the underside of the car and quite exposed to the elements - surely it would make sense.
Peter