#4 - The Biography Of ???

Riddle: If someone were to write a biography about us, the following could be reported: #1 - Some people claim we can cure hiccups. #2 - If you are down and a little blue, you might be experiencing me. #3 - The four of us are hidden from view and are waiting for you --- underneath your car. #4 - E.C.T., not etc., has this frightening therapeutic nickname. #5 - Not trying to sound corny, but we are often seen at farmer's markets, roadside stands, and garden centers, especially in the Fall. Based on the biographical information above --- Who/what are we?