They put a canopy over the truck bed.
We put up an awning in front of the shop to shade it from the sun.
It started raining, so I folded up the top.
In summer, people often drive with the car's top removed.
Used because a 幌 (canopy/hood cover) is a thin, sheet-like piece of cloth.
Standard kanji spelling.
Kana spelling is sometimes used in informal writing or when the kanji is not at hand.
The origin is uncertain. The kanji 幌 is used phonetically, and the word may be related to the idea of something that flaps or covers.