In the uk a series wouldnt really be a pinchable item, not much chance of a joyride and the parts are not expensive new, and they tend to have a small market, not the sort of thing you sell in the pub, NZ might be diffo.
A wheelclamp is a good visual deterrant, a ballache to use, insurance companys like locks that lock the gearshift, apparently one of the most effective devices, a thief would have smashed yer window before noticing though.