I delayed for over a year before buying a space saver wheel for my Jazz last month. Price £153.76 inc. fitting.
Try as I could I couldn't forget the tyre on my last car, a Honda CRV, which exploded with a bang as I left the M23 going south. Earlier, on the M25, we'd driven over a small amount of shattered glass and I suppose had picked up a splinter which 50 miles or so later had worked its way through the tyre tread. No way would spray gunge (according to my computer's dictionary gunge is 'a sticky, viscous, and unpleasantly messy material') have been at all helpful.
Out of sight but not out of mind it's comforting to know that there's a spare wheel under the boot floor.