The gun laws here in ME are very short and to the point. I have referenced them many times before so please do a quick search and find one of my other posts to find the link for the actual laws.
Essentially what you are suggesting would be a violation of law if the gun was concealed and accessable. The way the law is written is that with out a CCW, you cannot have a gun concealed on or about your person. There is almost no case law to define "about your person" but generally speaking it is taken to mean that if you can reach it then it is about your person. Now if it is on the seat next to you and not concealed then you are fine.
SO, in a car with the gun in the glove compartment you are violating the law. In an unlocked case in the back seat out of your reach you are not. On a snow mobile and in a compartment, which I am assuming any would be in reach, would be against the LAW. In that case, in the compartment? Who knows? Better to just open carry.
There is also a law against having a loaded gun in a motor vehicle with out a CCW. I would assume a Snowmobile would be a MV since they can bust you for DUI. But you might want to check into that.
My opinion is worth what you paid for it. I strongly suggest you research the laws themselves before making any decisions.
