BERLIN -- A few camouflaged Audis arrived secretly from Germany early this year at a facility of electric vehicle maker Rivian in California, where some 30 engineers stripped the electronics and fitted them with the U.S. startup's harnesses and modules.
Intense testing followed at the Palo Alto facility of how the U.S. startup's architecture and software - controlling virtually every function - would work in the German cars.
The mission: to see whether future EVs from Audi parent Volkswagen Group could benefit from Rivian's advanced technology, two people close to the deal told Reuters. A third confirmed that some Audis were shipped to California.
The result: Europe's biggest automaker said on Tuesday it would pump as much as $5 billion into Rivian as the two automakers agreed to a technology joint venture.
The closely guarded deal took the auto industry and investors by surprise. Details on how it came about have not previously been reported.
"I think it's an accomplishment in its own right that this has not leaked, given the amount of work that has already happened... and the number of people involved across our teams," Rivian CEO RJ Scaringe told Reuters.