Entity Larry Alofs spoke thus:

> You definitely want to preserve the moisture barrier.  If you have to
> cut it, try to improvise with plastic from zip-lock bags or something.
> Seal  with tape; it's very difficult to glue polyethylene.
Not only that, but you need to fasten the plastic sheet down real well
because at a certain road speed it can oscillate like the reed in a wind
instrument. You don't want that to happen on along trip!

--Gnarlie