Formula Vintage G2 is a semi-fictional class in Automobilista 2 that's based on the 1970 F1 season. Both Lotus 49C and Brabham BT26A appeared together only during that year.
This era of F1 is a short transition phase between wingless cars from the 1960s to more aerodynamically shaped cars from 1970s. For a brief couple years the cars still looked like 60s F1, but had wings attached to them.
Afterwards car design moved away from the familiar 60s tub shape and this era of more effective aerodynamic design is represented by the F-Retro classes in Automobilista 2.