Answer: rideshotgun

AnswerCrossword Clue
RIDESHOTGUN

Guard the strongbox, in westerns

RIDESHOTGUN

Sit beside the driver

RIDESHOTGUN

Sit up front

RIDESHOTGUN
Not take a back seat to anyone?
RIDESHOTGUN
Accompany in the front seat
RIDESHOTGUNTake the passenger seat
RIDESHOTGUNNot be in the driver's seat
RIDESHOTGUNA back-seat driver can't do this