I was having the same quandary...
The tub of goo in my boot is over three years out of date. If I'm honest, I've not much faith in the idea anyway, but using expired solution really isn't going to help my mood when I've got a flat: gunk all over me and the car, and still can't drive away. Then there's the battle with the tyre fitter to deal with the mess and disposal of a load of goop of unknown composition.
Anyhow, I contacted three dealers to see what a replacement tub of IMS would cost me. I hoped to pay about £25 quid, but was expecting it to be more like £50. I was less than amused when they all came back at over a hundred plus VAT ( see also
HERE ).
One helpful chap in the parts department (who seemed genuinely embarrassed at the price) suggested an additional £25 quid would get me the spacesaver kit. A reasonable suggestion, but I'm motoring on a shoestring at present so I was looking for the price to go down not up.
A metal wheel was much my preferred option. I removed one of my Pentas from the car and stripped out my boot and found it fits (other members have had varying results). It's tight, but a 16" wheel with 205/55R16 tyre does go in and the lid closes without modification. The jack can stay put and the dish of the wheel will hold a few ***orted tools.
Used alloys (some with tyres) can be had from popular e-auction sites for 30 to 60 quid a piece. A steel wheel would have done, but I've found information as to what might be suitable (PCD & offset) to be thin on the ground.
Eventually, with some last second bidding, I secured an unused spacesaver from a few miles down the road for £50. Not quite as versatile as a full size wheel, but the price was right, and it leaves a bit more out-of-sight space under the lockable boot flap for junk.
