While this prototype is most likely Lexus' new mid-size sedan, rumours swirled around the internet earlier this year, driven by reports out of Russia, claiming Lexus was about to give the GS the chop, with the front-wheel drive ES stepping up to take its place in the range.
It's possible, due to economic conditions, the report may hold true for the Russian market. If these reports are correct on a global level, this car could be a prototype of a Japanese domestic market model, possibly a member of the Toyota Crown family or the due-for-replacement Mark X.
Should this turn out to be the new GS, this prototype indicates it will have a slimmer version of the brand's spindle grille, as well as a fastback-style rear-end and a more dynamic look for the exterior.
Regardless, this prototype most likely rides on a version of Toyota's new GA-L platform for rear- and all-wheel drive cars. Already used for the latest LS sedan and LC coupe, GA-L features a mix of lightweight materials to improve fuel economy and performance.
Turbocharged four- and six-cylinder engines are likely if this is the GS. As indicated by the yellow sticker on the prototype's rear, this prototype is motivated by hybrid drivetrain.