Free fuel with 4 day hire @ Thrifty
And here's another option.
Take a 4 day hire with thrifty at Surfers Paradise, Gold Coast Airport, Woodridge, Coorparoo and Cleveland and you can dump it back empty of fuel.
Its a bit of a toss up to decide whether you're better going for the hire three get one free or this. I figure the cost of a tank of fuel has got to be in the region of $40 for the car that the offer is available on. So at $49 a day for hire its about the equivalent of hiring it for another day.