Founder RJ Scaringe said Rivian is working on something related to the Amazon investment, but hinted to Bloomberg that it may not be a vehicle. He's open to selling his company's technology (it has developed long-lasting batteries) to other businesses for various products, including stationary batteries. So perhaps Amazon is interested in using Rivian's know-how for something other than vehicles, though it has also invested in a self-driving car startup.
Scaringe noted in the interview that tens of thousands of people have laid down a $1,000 deposit for Rivian's EVs, just over half of which are for the R1T. That pickup and the R1S SUV are scheduled to go on sale next year.