I also have the Radiance. "Not street legal"? Please explain...
The DOT rules for "street legal" include testing for brightness at different angles and distances to the lenses. One of these tests is a measurement off to the side a specific number of degrees from center. Due to the way light is created and focused by LED lights, they (mostly) cannot pass these tests, hence not "street legal". LED lights , in general, have very little side bleed. There is also a fee for "street legal" certification, which adds to the cost.
These tests were created when LED lights did not exist, and haven't been updated since. LEDs are brighter (in many circumstances) and more energy efficient, but government moves slow and doesn't adapt well.
As far as new vehicles, the manufacturer is responsible for certification, and can design lights however they want. Many still use incandescent lights to avoid lens / light redesign.
