back-seat bullet
n.— «However, unbuckled passengers aren’t the only threat to those in the front seat. “Anything that is not restrained or tied down will be thrown forward,” he said. “We’ve coined the phrase ‘back-seat bullets.’”» —“Review raises questions about drug studies on rats” by Paul Taylor Globe and Mail (Toronto, Canada) Dec. 29, 2006. (source: Double-Tongued Dictionary)
Further reading
Twice a day the River Thames recedes, revealing a muddy shoreline. Hobbyists known as mudlarks stroll the surface searching for objects that have found their way into the river over the centuries, everything from ancient Roman jewelry to modern...
Jim in Columbia, South Carolina, has noticed sportscasters’ use of the phrase on the season with reference to a period of time. This construction shows up in the sports pages as early as the 1880s, first referring to a team’s revenue and...