Rivian and Volkswagen Group have finalized a multibillion-dollar joint venture to develop software, paving the way to let the German auto giant leverage the EV startup’s more technical chops in the coming years. Volkswagen will invest up to $5.8 billion by 2027, about 16% more than when the deal was first announced in June.

The new agreement, which builds on an earlier announcement, calls for the German automaker to invest $5.8 billion in Rivian, a maker of electric vehicles.

The companies said the deal is now up to $5.8 billion, with the first VW models to use Rivian's software and electrical architecture arriving as early as 2027.