They said they plan to sleep in their SUV, a five-year-old Chevy Tahoe, into which they’ve packed boxes of important documents, bags of clothes, some foodI mistakenly added the word "and" between the serial comma and the last item in the series, which is actually unnecessary. Below is an excerpt from the ClearWriter website.
"Dropping a conjunction has the opposite effect of adding a conjunction: creating a series that is not exhaustive, but a mere sampling of possibilities. It also makes your reader see the parts of the series as more separate than joined.
This 20th century is baffling, difficult, paradoxical, revolutionary."