This device, the DR 56, comes with a glass antenna. With this I have perfect reception, even if they still packed is in the car. Sticking I will only at the next opportunity. An outdoor antenna with magnetic base is in my opinion, not necessary.
Sound and output level of the device are hervoragend, much better and louder than the headphones out of pocket radios.
Power is supplied via the USB connector of the car. Thus, the radio will automatically turn on when I start the car. The device still also has an FM transmitter and a Bluetooth handsfree. Both I do not use, because my car has an auxiliary input and a speakerphone.
Hence my recommendation: this is the only viable DAB + car radio and its price absolutely worth it.