when did cars start having passenger side mirrors
Wing mirror In the 1940s many roads were unpaved and had two lanes, one in each direction. Drivers had to be aware only of traffic on their side and directly behind them (rear view). Due to this, most passenger vehicles with an internal rear-view mirror until the late 1960s had the passenger-side mirror only as an optional addition, as it was considered a luxury.
Left- and right-hand traffic In the late 1700s, traffic in the United States was RHT based on teamsters' use of large freight wagons pulled by several pairs of horses. The wagons had no driver's seat, so the (typically right-handed) postilion held his whip in his right hand and thus sat on the left rear horse. Seated on the left, the driver preferred that other wagons pass him on the left so that he could be sure to keep clear of the wheels of oncoming wagons.[13]