There's a big pineapple on the sunshine coast, which according to their website (yes, it has a website) is 'Australia's most famous Iconic Queensland tourist attraction and landmark.' Don't go there. And don't go to any of the other big things created as some form of distraction along the Bruce Highway. The fact that anyone ever felt the need to build these things should set alarm bells ringing as to how there is to see and do. Unless you just want to drink your way up the coast, in which case I can suggest a few bars.
In all honesty, I'd strongly suggest going inland to the red centre, and then up to Kakadu, across to the Daintree and Cape Tribulation then south to see the Great Barrier Reef, and exit swiftly through Cairns. It will be a much more interesting, beautiful, memorable trip than hitting the coastal road.