Dont necessarily take it for granted that because they say big rig suitability they are , ask a lot of questions , it may save you driving out of your way.
We have a van around same size and have driven away from some parks as they have sites that will fit the van but the access is way too tight
I am very capable when reversing vans , I very often back others vans in position as we manage parks and its part of my job.
But backing back and forwards in between cars , trees and other obstacles can test the best of drivers
we find free camping is usually a lot easier (most times) as parks tend to squeeze vans in .
In the camps books and Wiki they state the size . I have found popular grounds can use size as a way of limiting or screaning . I have large exhaust on V8 diesel . Not that it's run at all in camping grounds .
If you are using caravan parks, then it may be prudent to book ahead, just in case they are full When booking just ask if they have a site suitable for your rigs
As Possum3, and Aus-Kiwi have already mentioned, the Camps Australia Wide books have a symbol showing if a caravan park/budget/free site, are suitable for big rigs
We traveled 5 years full time with a 30' 5th wheeler towed with a truck all over Oz, the simple answer is plan your route, ring ahead, and explain that you need a big spot if possible.
We never got knocked back and even ended up in prime waterside spots, as most CP's want your business and will normally bend to get you in somewhere, so long as it's not silly school holidays.
We were actually put on the CP managers front lawn at one mid north NSW coastal CP and had the prime position for 3 weeks. There was no way we could have got in the proper park.
Another trick is look on Google earth at your proposed CP and check out access etc. Google earth pro is best as it can be zoomed in far greater than the basic one and was free a while back.
The advertising of 'big rig' suitability can be misleading. We stopped in Port Macquarie, rang and checked that we could get the bus in. No worries, we would fit. And we would have, except that the turning space was too small, we couldn't swing enough to get in. This wasn't the only place we struck this problem, but it was definitely the one that got me thinking, and led to increased questioning of CPs when I enquire about big rig suitability.
Where possible, we stop at showgrounds, always have plenty of wriggle room there.
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The Mobile Madhouse: me (Rosie), him (Troy), a kelpie, a kelpie-dingo, a husky & a rainbow lorikeet.