Coastal driving and Salt.
Residual salt (like the cold climates and snow) is usually is often dumped in large quantities by a southeast wind with cyclone condition surf on Coastal regions.
Driving south on any of the coastal strips in SEQ during a big SE swell and wind and then when you stop, taste the salt on the windscreen.
Add a bit of rain and this is getting driven into every nook and cranny under the car, but most don't think twice about it ... really the beach is no different (apart from the sand blasting of the existing Factory rust protection).
If you live in QLD and you are near the coast your car is probably not the 'salt virgin' you think it is .. In saying that (being a humble opinion only) I have had two vehicles RRC and D1 both wither away to wrecks due to rust in sills and floors from beach use.
I am about to use Electronic (unsure if its a hoax or not - but willing to take a gamble) and underbody rust prevention on a D3 shortly for both of the reasons above (IE coastal road driving and beach driving - the main reason for purchasing the car.)
Take the car and enjoy the trip, in my opinion, You'll have a mate to help if you get into any trouble and if you keep out of the water, your no worse off than taking a drive to Noosa (when its pumping) on the David low way.
your decision of course.