No such thing as secure with something that size really mate.

But its only really for our own use, if we start letting loads of people park cars in there and arent allowed to give anyone else keys to get onto the land (fenced all round) where the property is anyway, its in the lease, and it will look like we are doing something commercial with it if loads of random cars turn up, so not really an option anyway, especially not for long term storage. Sorry mate.

Shame cause would be fucking mint to have about 100 people all using it as a massive shared workshop, always someone there to lend a hand or borrow a tool off or talk bollocks to etc!