Bear with me, so you have a puncture, take it to the local shark who sucks his teeth and says "sorry bud, can't fix this one". Obviously I'm completely surprised at this, yea right. So you think, ok, there's quite a few miles left in the other one, I'll keep it as a spare and  have 2 new ones but you can't, you only have 4 alloys. Oh, and the toytown spare in the boot. The only option is to keep the rubber cept it can't be used as a spare. Do I search for another alloy or give up?

 

You can fit a full size wheel in the spade wheel well, so if you can find one in the same style do that, I know 17s fit but do need some foam to pack the floor out to make it level, your 16s should be ok though.

I got a full size 15" to match the rest of mine but still makes the boot carpet uneven but well worth it, you can get a 15" wheel and fit a higher profile tyre for cheapness to give the same effect as a 16 or 17" wheel and tyre if it's just to be able to drive at motorway speeds until you get a puncture fixed or replaced