GM introduced a revised sedan at Auto Shanghai 2005, designed in cooperation with PATAC. Bearing the internal code T250 and sold in South Korea as the "Daewoo Gentra", the revision comprised primarily interior and exterior styling changes, a new interior instrument panel and minor equipment changes, including increased sound deadening. Incorporation of the radio antenna into the rear glass and extensive wind tunnel testing helped reduce the coefficient of drag from 0.348 to 0.326.
A restyled hatchback with the sedan's updated instrument panel was presented as the Chevrolet Aveo during the Frankfurt Motor Show 2007, to be marketed in Europe and North America. The Korean market received its own distinct restyle of the hatchback, the Gentra X.
Later iterations, including the Kalos, Aveo, Barina and Gentra sedans, the Gentra X hatchback and the 2007 "Frankfurt Show" hatchbacks were styled in-house and with the assistance of PATAC, and depart notably from the original Giugiaro exterior and interior styling designs.
With launch of the Gentra X in South Korea, GMDAT had replaced engines of T250. 1.2 L S-TEC II inline-four engine was updated with features such as dual overhead camshaft (DOHC) and timing chain (older version has timing belt) system. 1.6 L E-TEC II engine had replaced with ECOTEC (GEN-III) engine with new features such as variable valve timing mechanism.
