Tesla Car Radio. The all-glass roof extends from front to back, creating a sense of openness from every seat. The Audio amplifiers are made in Hungary, while the speakers are made for Tesla in China.
Note that Sirius pays OEMs to install the radios, so it does not cost much to provide it - Elon just hates the shark tail. Tesla cars are known for futuristic electric styles with huge infotainment touchscreen systems. It brings some of the strengths of each while dropping the weaknesses.
Most of the equipment appears to be created specifically for Tesla and is not a rebranded product.
Retain most vehicles' factory steering wheel control, backup camera, etc.
Note that Tesla isn't the only car company experimenting with removing broadcast radio. TuneIn Radio on the Tesla Model S blends Slacker Internet music with AM/FM Radio. In contrast, in FM radio, the carrier is frequency-modulated; the radio can reject amplitude-varying noise.