In addition to building cars and trucks, Hyundai does the following:
* building construction (everything from homes to office and factories)
* civil engineering (bridges, dams, shipyards, etc.)
* trains of various kinds
* military vehicles, including tanks
* construction equipment (cranes, etc.)
* manufacturing equipment (furnaces, presses, etc)
* shipbuilding (both civilian and military)
* shipping
* offshore oil rigs
* powerplants and electrical grid equipment
* has a large retail department store chain
* insurance
* chemicals and plastics
* lighting
and, of course...
robots (currently just industrial and medical)
Steel making and mining, talk about vertical integration!
Much more. "It is the second largest South Korean chaebol or conglomerate, after Samsung Group, related to other Hyundai-name industries following a specialized development split and restructuring which resulted in Hyundai Motor group, Hyundai Heavy Industries Group, Hyundai Development Company Group, Hyundai Department Store Group, and Hyundai Marine & Fire Insurance."[0]
They even build ships and oil rigs.
Robots are used to make cars. Robots and cars both require precision engineering at a macro scale. Both have lots of electronics and control systems, even leaving out self-driving or autonomous capabilities.
For 5% of Hyundai's market cap, I think you can make a case for BD being valuable to Hyundai just as a car manufacturer, or having synergies with its core business.
Edit: they make them - https://www.hyundai-robotics.com/