The National Highway Traffic Safety Administration says the G-Wagens may not have updated engine control-unit software that is supposed to limit reverse speeds. As a result, thanks to that big ol' 6.0-liter, 621-horsepower biturbo V12, "While in reverse, any abrupt changes in steering while exceeding 16 mph may cause the vehicle to become unstable," with a high risk of a rollover.
NHTSA advises affected owners notified by Mercedes-Benz to take their $220,400-plus G-Wagens in to dealers for a free software upgrade.
Mercedes unveiled the 2019 G-Class in January at the Detroit Auto Show for sale starting later this year. The new Mercedes-AMG G 63 does away with the solid front axle in favor of an independent double-wishbone suspension and electric rack-and-pinion steering, plus a strut tower brace around the V8 to improve front rigidity.