Compare an airport pickup vs. a town pickup. Grabbing a car in town is often cheaper, but remember to add the cost of the airport shuttle to see if you're actually saving.
A standard car is all you need to get to the main sights in Cape Range National Park. You'll save money on rental fees and fuel compared to a big 4WD.
If you're visiting during the popular whale shark season (April to October), book your car months in advance to lock in a better price and ensure you don't miss out.
Staying for a week or more? Look for weekly discounts. Sometimes renting for a full 7 days can be cheaper than for 5 or 6, so it pays to check different rental lengths.