It looks like my family will have a one-day layover in SYD next year. We'd like to take the kids on a quick tour of the sights. I'd much prefer to just take the Airport Link into town. But even if I get a discount on the kids, the train is expensive. In contrast, I can pick up a rental car at the airport for basically nothing using my Hertz points. Would I regret doing so? And I recall there are some "cashless" tolls I might run into along the way. Would that be a hassle/expense to deal with?