Answer: getahorse

AnswerCrossword Clue
GETAHORSEOld-time advice to a motorist.
GETAHORSEBon mot to a motorist, circa 1900.
GETAHORSEExhortation from early Maxwell days.
GETAHORSEAdvice to a pony-car owner?
GETAHORSETaunt to an early motorist
GETAHORSETaunt in early motoring