I'll start working on the loan application now Tom lol...

Sue - the door cargo box has a maximum interior height of about 15-16 inches. The minimum height dimension for a 10 lb. tank seems to be about 23 inches so that won't work. A fatter shorter tank wouldn't fit either.

Horizontal storage / vertical inflation seems like a viable option. Only thing that sucks is that a full tank weighs about 37 lbs., so taking it out each time would be painful.