As soon as I got my Jazz I fitted a (home made) expanded aluminium metal grill over both apertures in the front bumper.
I once got stuck behind a road gritter on a motorway and my condenser was plastered with rock salt impact craters. Fortunately, it wasn't holed.
I notice on Halfords website, they appear to sell Ripspeed Black Stretch Grid Competition Mesh for hefty £25, finished in black. B&Q and Wickes appear to sell galvanised mesh for around £8.
Excuse my ignorance, but can you explain how you attached your DIY grill to your Jazz?
ie. did u somehow attach it to the rear of the front plastic bumper, or did you bolt it to the car's chassis?