I believe any business will be successful. The key is locating the correct market. Try using Google insights to see where searches for dune buggies and Sand rails are originating from. Once you locate the area(s) that have the most searches for those terms, start researching if there are any SUCCESSFUL dune buggy and sand rail businesses in those areas.edit: I searched for you and it seems that the Australia is a great market, along with North and South Dakota
Wow they do sound like fun, I would also look at hiring out Dune buggies as a way to keep the income coming.I guess the biggest issue you would have is location, Australia has some great places to have fun in the sand, but you need to ensure that they are not protected areas, Would you also consider selling the buggies in Kit form so that others can build them themselves again, you can then benefit from selling replacement parts etc.If you really want to find out what sort of demand there is for your business and how much people would pay for, then there is a company called Idea-Testers in Australia that I have heard of that can do the research for youWish you the very best of luck
It depends on 3 things - location, location, location.