This question already has an answer here:
Let's say someone is a constantly travelling truck driver. He has no firm "home" other than his truck, so he sleeps in his truck.
My rav explained that if someone rents a home and is there for more than 30 days, he is required to place a mezuzah.
Two scenarios regarding the truck driver:
1 - He sleeps in the back seat of the truck cab. He owns the cab. It seems that this would be considered his "home". Or, is there a minimal required spacing needed to define a dwelling and the cab is too small to fit this requirement?
2 - He sleeps in the trailer part of the truck. However, the trailer is shlepped from one haul to the next one. He might have the same trailer for 30 days, depending on his assignment and how long the trip is. He might have that trailer for only 3 days after which it is detached and he gets a different trailer.
Should he move the mezuzah around from one trailer to another or is he considered as if he never has any type of permanent home and would always be exempt from any mezuzah?