For those of a younger vintage the 1960s Mustangs and other horsey name cars were known as "pony cars"
So it does travel ;-) Takes the name from the early Mustangs, but we still use if for small-ish muscle cars with a long hood, a short trunk and a back seat only suitable for a box lunch. Cameros, Firebirds, Chargers... Seems appropriate for a short scale bass painted like yours...