I do no that if the truck cap is over so many inches above the cab of the truck you fall under the self contained rules.
P town is not like the other beaches there is desinagted ares for contained veichiles.
I know this because my bud got his sticker taken away because he was down at hatches cove with the other trucks and his cap was 12" over the cab.
They told us that we were not to go past the camper area with his type sticker.
The park rangers down there are Dic*s
They would just put a tired fisherman out on the road than to allow him to sleep for a 1/2 hour. and if caught sleeping in a truck you will have your sticker pulled.
AND DON"T GET ME GOING ON PLOVERS
