Andersson – who in the autumn took his first podium in the Rallycross World Championship – has been the series' official reserve driver during the year.
In Chile, the 22-year-old got the chance when the German Jutta Kleinschmidt crashed in the qualifier.
The Swede contributed strongly to the team with four-time Dakar winner Nasser Al Attiyah, Qatar, taking first place on the podium and finishing third.
- We saw that the momentum was there in Chile.
Now we are building further, says Klara Andersson.
Johan Kristoffersson - now five-time world champion in rallycross - and Mikaela Åhlin-Kottulinsky, lead before the decision.
The Swedish pair are 14 points ahead of Sébastien Loeb, France, and Christina Gutiérrez, Spain.
Brothers Timmy and Kevin Hansen are also in the series.