Hi Joe, and welcome to the club.
That's an awful lot of replacement bulbs you've endured there
I'm assuming that XVW 100/099 are the reg plates on your i30s, if so the 099 seems to be suffering more, by a factor of 2-to-1. Are they driven over different terrains?
You mentioned they were all replaced under warranty; that suggests Hy are admitting liability
in some way, otherwise why would they change them for free?
As Rusty infers yours isn't an isolated case; we've had members with similar (although not quite as severe) bulb issues. In a couple of instances the voltage at the filament has been shown to be too high under spike conditions. If it were me I'd couple up a voltage recorder and monitor it over a couple of weeks; however, unless you already own or have access to one, that would be false economy. Do you have any independent autoelectrical dealerships nearby in Vic? Just thinking out loud, maybe they could advise...
Good luck.