Can anyone advise the best car hire companies to use in Australia ? We are looking at booking for short blocks of days a couple of times along the trip - e.g. Gold Coast/Sunshine Coast , then later in Cairns again etc

I picked up a Hertz rental at the Cairns airport and dropped it off in Townsville. There were four days when didn't use the car, but only having one contract for the entire duration ended up being cheaper.

We used Hertz as well, great to work with IMHO. We had the car for just over 3 weeks and put over 3000 miles on it. We chose unlimited mileage, and the upgraded us at the same price from midsize to larger
vehicle.

"We had the car for just over 3 weeks and put over 3000 miles on it."

Just out of curiosity, that was 3,000 miles and not kilometres? Australian odometers and speedometers cars are of course calibrated in the latter.

The big local players are Hertz; Budget; Avis; Thrifty; Europcar.
In Sydney & Perth, I like Bayswater Car Rentals http://www.bayswatercarrental.com.au Baywwater has lower CDW excess and waiver than the majors.

An Australian owned company at the Gold Coast looks interesting & I'm trying them this weekend:
www.economyrentalcars.com.au

Emilia1 - you might like to note that advertising is not allowed on this forum.

I've always found I get a good deal with www.standbycars.com.au

We have used Budget, Hertz and the last time we went, I used a service called carhire.com or such which is an aggregator, I think. Happy with all! And, that's one thing we realised driving from Sydney to the Gold Coast (over 5-6 days) - that's one BIG country! Be prepared!

It was miles as figured by the "male" in our party. We often took off at 4am and drove most of the day stopping here and there along the way as we were stopping at a lot of rural farms to see the horses and discussing breedings etc. and\or following our hosts around the country side. I never looked at the miles, I just checked the gas and drove. Being from California its nothing to do 500 miles a day in some parts.

I can highly recommend Economy Rental Cars at the Gold Coast airport. Australian owner-operators whose rates and CDW waiver are far below the big operators. Excellent service.
Pre-book, call them when you arrive & they bring the car to you immediately.

I rented a Hyundai Getz for 2 days last weekend - $70 including CDW waiver.
www.economyrentalcars.com.au

Good advice on Gold Coast car rentals - I'm taking the elderly aunt there later in the year!

Can't speak highly enough of them, Margo. I committed the ultimate stupidity & noticed my mobile sitting in the console ... 30 seconds after I'd locked the car & shut the boot, when I returned it after hours. Quick call to Economy & all was set. Next morning, I had a re-assuring phone call just after 8:30 and had the mobile back first thing Wednesday morning. No postage charge. Husband & wife team - been in business about 20 years. Nice people doing a great job.

Not so the "Airport Lounge" - but that's a story for another day.

Another good thing for Travel with Aunt: No pfaffing around doing paperwork while Aunt stands at an airport counter; looking for the car etc. You just call Economy when you arrive, go stand across the road from the Taxi rank (before the bus pick-up) and they whizz around & collect you, take you back to their office (near the University turn-off within the airport precinct), where you can sit down & do the minimal paperwork.

Thanks, Bokhara - I've already got my quote!