The knee jerk reactions are ridiculous. I'm not proposing anything for first time offences, or second time offences. Third time causing an accident whilst drunk? Something needs to be done and I simply proposed one option.
I know a dickhead who had to go to the police station DAILY. A simple way of monitoring it could be daily visits to a police station, sure, he can drink a few without getting caught but if someone has to be at the police station at 7-8am every morning then there is no way they could get drunk the night before. Yes, they might just get drunk in the morning after going to the police station but this is a better alternative to JAIL.
It's not that hard to implement. A possible system:
Certain mechanics can do the safety checks. They forward the results to QLD Transport, QLD Transport flags your rego as a "pass" and sends out the rego renewal. You must have the check done before your rego expires.
I think that'd make for a fairly cheap system, costs QLD transport very little I'd imagine.