I see many people saying "just pay it." It's hard to argue with that advice from a legal or practical perspective, but you seem to fail to grasp other considerations, namely the size of the fine. It is easy to write off a $50 parking ticket just as we do here at home. But a $350 fine for driving 5kph over the limit is a sizeable amount for many people. This may be pocket change to some people but quite a bit to the the backpacker surviving on $50/day (or whatever it costs now). So it isn't necessarily a matter of trying to get away with something (though no doubt that's true for some), but also a financial issue. Not to mention the additional issue of fairness when you don't trust the equipment or the minuscule margin of error.

You were lied to, as discussed above. None of us alleged violators have had problems obtaining e-visas to Australia.

Maybe in Switzerland. But as noted above, the worst case scenario is that you are detained and asked to pay - which hasn't happened to anyone here if I read this thread correctly so it's really a remote possibility at this point.

As noted above, officials do not consult the database when you exit the country. I suppose you could be flagged as is done in the US, but this is normally reserved for high value fugitives, doubtful on a speeding ticket.

Would be easy for the government to simply autocharge the rental company (as is done in the USA) which in turn can pass the cost on to the individual. That's the most likely scenario.