I know when I bought my campervan, when I signed the contract, the salesman did say "You have ........hours to change your mind if you want to cancel the sale" This is in Vic and I can't remember how many hours.
I entered into an order to purchase a new caravan with Echuca /Moama caravans and was advised by the salesman that it was not a contract and I could get out of it if I wanted.
I did cancel the order and took my van which I traded in, back and also got my cash deposit back.
The only valid advice anyone on this forum can give is to get "legal" advice.... Maybe your state's fair Trading Department or it's equivalent would be a place to start
We are in NSW. According to Fair Trading Dept the contract is binding. Some dealers offer a cooling off period, but they don't have to. Luckily we have got out of but with a lot of hassle and we were seriously abused by the dealer!!! Won't recommend them to anyone.