Do they let trucks park overnight

To my knowledge they do let them rest there.

Well, is the "officially" or "unofficially"? Nearly EVERY Wal-Mart, especially SuperCenters, will let RVs, Big Rigs, and others to park overnight, but this is an "unofficial rule"... If you ask permission, except waiting for Auto Parts, Pharmacy or MurphyUSA to reopen, the answer is "no, we can't allow it". Some Managers will actually come knocking on your windows, at some locations!