Gas Monkey's Birthday and he turns OLD

My F.M.I.L (future mother in law, for future reference) and I are thinking of holding some sort of birthday party for Gas Monkey. He turns the scary 3-0 on the 19th of December. So does anybody have any ideas of what we should do for him? It will likely be at my house, but it is a little small for a lot of people, especially if nobody can go outside due to the weather (but we'll keep our fingers crossed). He does not want a fuss, but that is one birthday wish he won't get. Sorry pal. Instead we'll make him wear a birthday crown and sing to him in front of a cake (maybe in a creative shape like a boat or a dinosaur, or a piece of elephant poop). Oh this will be exciting.