Just be careful that your insurance company will cover you if you have a gas bottle in the vehicle. Some refuse to and it would be terrible if they used it as an excuse to avoid paying you out if the unthinkable happened and your Kombi was written off in an accident. Following a serious accident, the police gets very uncomfortable if they notice a gas bottle in the wreck. In fact they'll make so much fuss over it that your insurance company will definitely find out about it. Food for thought, but it would certainly pay to ask your insurer beforehand.