"future flying car will weigh far less than our present-day cars. The entire upper part of the body will be enclosed in an unbreakable, unburnable, glass-like substance. This is quite necessary, particularly for the ..."
"likewise instructions and plans, for making a flying car with wings, in which a man may sit, and, by working a small lever, cause himself to ascend and soar through the air with the facility of a bird..."
https://books.google.com/ngrams/graph?content=flying+car&yea...
Starts in the 1750s, though some of that is simply justipostion of the words "flying" and "car", often with intervening punctuation.
A 1923 article: https://books.google.com/books?id=BcIrAQAAMAAJ&q=%22flying+c...
"future flying car will weigh far less than our present-day cars. The entire upper part of the body will be enclosed in an unbreakable, unburnable, glass-like substance. This is quite necessary, particularly for the ..."
And from 1810:
https://books.google.com/books?id=P_AOAAAAYAAJ&pg=PR3&dq=%22...
"likewise instructions and plans, for making a flying car with wings, in which a man may sit, and, by working a small lever, cause himself to ascend and soar through the air with the facility of a bird..."