Why do you want an alarm on your Jazz - nobody is going to nick it, it just isn't the kind of car to attract either boy-racer or high end car thieves - and anyone in between those two groups will never get past the standard Honda immobiliser anyway.
I have seen cars on car parks with the bonnet up with the alarm going off, with someone fiddling around under the bonnet and people just walk by (including me). There are too many alarms going off every day and people just ignore them now, every week we have house alarms going off in our street and no-one even bother checking any more, I certainly don't but I would love to go and cut the cables to the sirens.
If you are that worried get a GPS tracker off e-bay and fit that, my mate fitted on to his sports car and they do work surprisingly well.........