Hyundai Motor Group has invested in Aurora, the latest sign that the scope of the year-old partnership between the automaker and self-driving car startup has expanded.

Aurora and Hyundai didn’t disclose terms of the investment. However, picking part new details of its Series B funding round and speaking to sources within the industry, Hyundai’s investment is below $30 million.

Aurora announced in February that it had raised more than $530 million in a Series B round that was led by Sequoia Capital and included “significant investment” from Amazon and T. Rowe Price Associates. Since then, that Series B round has expanded to more than $600 million with new investment from Hyundai, Baillie Gifford and the Canada Pension Plan Investment Board, TechCrunch has learned.

To date, Aurora has raised more than $700 million, a figure that includes its seed round Series A round of $90 million.

Hyundai’s stake in Aurora is an affirmation of the company and their working relationship. But it’s just one measure. What Aurora is actually doing matters as much.

When the partnership was first announced in January 2018, the details of the relationship were scant. New information reveals that Aurora has been working with Hyundai and Kia for the last year to integrate its “Driver” into Hyundai’s flagship fuel cell vehicle NEXO.

Aurora says it will expand research and development of a self-driving platform for a wide range of Hyundai and Kia’s models.

Aurora, which launched in January 2017, works with companies like Hyundai, Byton, and until more recently Volkswagen, to design and develop a package of sensors, software, and data services needed to deploy autonomous vehicles. The company describes this “full stack,” (an industry parlance) the Aurora Driver.

Aurora, like many of its competitors, are focused on Level 4 autonomous systems with an eye toward Level 5. Level 4 is a designation by SAE, the automotive engineering association, for autonomous vehicles that take over all driving in certain conditions. In Level 5 autonomy, the vehicle is self-driving in all situations.

About a year after Aurora’s official launch date, the company announced partnerships with Hyundai and Volkswagen, followed by a Series A funding raise that resulted in two new board members — LinkedIn co-founder and Greylock partner Reid Hoffman and Mike Volpi, former chief strategy officer at Cisco and general partner at Index Ventures.

Volkswagen has since ended its partnership with Aurora. Meanwhile, Fiat Chrysler Automobiles has announced a collaboration with Aurora to to develop self-driving commercial vehicles. The partnership with FCA will focus on integrating Aurora’s technology into the automaker’s line of Ram Truck commercial vehicles, a portfolio that includes cargo vans and trucks. The deal could extend to FCA’s Fiat Professional brand as well, TechCrunch has learned.