From ibikeu Wiki

Four-wheelers, not to be confused with a quad/ATV, this is generally a slang-term used by truck-drivers, when they complain, or refer to automobiles with only four-wheels. Cyclists tend to lean towards the use of "Cage" or "Cager" when referring to the above vehicle, but most also think the aforementioned term sounds appropriate as well. This term does not refer to Bike Cars such as the CRANK Mobile.