My fiancee (Padeye) and I were having one of our typical discussions the other day, when the concept of “jalopy” came up. We decided to ask the Straight Dopers two questions along this line: (1) does anyone here know the origin of the word “jalopy?” (2) what exactly characterizes a real jalopy? Thanks. 
My fiancee (Padeye) and I were having one of our typical discussions the other day, when the concept of “jalopy” came up. We decided to ask the Straight Dopers two questions along this line: (1) does anyone here know the origin of the word “jalopy?” (2) what exactly characterizes a real jalopy? Thanks.
The origins of the actual word are unknown.
It appears in print around 1925 By 1929-35 it was pretty common and meant an old car, battered usually. The spelling was obviously phonetic as it varied from print source to print source. It also was used to describe a 12-passenger airplane in 1931. Don’t know what to make of that.
A jalopy is an older car which runs poorly.
Thick blue or black exhaust is a good sign of the latter requirement 
M mother once said that a jalopy was a car that you could hear or smell before it was seen.
A jalopy is any car driven by Archie Andrews. 
Someone’s been reading Archie comics…
I think a jalopy can be any motor vehicle that’s dilapidated.
How many motor vehicles are made of stone?
Completely from stone? Fred Flintstone’s car was logs, skins (toneau cover) and stone IIRC.
The word is from 1920’s America…at that time, the US exported a lot of used cars to Mexico. These were shipped through the port of Jalapa, and the longshoremen corrupted “Jalapa” to “jalopy”. It is a slang word meaning any old, busted-up car.
You have the source and evidence for that, I suppose? Otherwise it remains one of many guesses, and ‘jalopy’ is still ‘of unknown origin’.