Roma, Chinchilla, Dalby, Bell, Kingaroy, Goomeri, Gympie, Rainbow Beach. There's a few good campsite's at Bell, Kumbia and Kingaroy which is a bit over half way if you need to stop overnight.
When you get close to Gympie it can sometimes pay to ignore your GPS and just follow the Rainbow Beach signs as some get given the scenic tour.....if you want NP beach or camping permits buy them online the savings will buy a couple of beers.
Goomeri showground is a nice little spot close to town also.
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Checking out the places I drove past a thousand times................