The DAB radio is the main draw, however. Simply twist the main knob to cycle through available stations, and press in to select. We found reception to be excellent, with lots of stations being picked up in the areas we tested around London and the Home Counties. You can also quite easily store presets using the favourite button on the top. Press once to call up the listing, find an empty slot, then press and hold down to store the current station. Up to 30 presets can be stored, and recalling one merely entails scrolling through the listing and pressing the knob to select.
The Highway 300Di has some other tricks up its sleeve, too. The playback controls work with DAB radio as well. You can pause playback, and the unit will buffer up to 15 minutes of audio, depending on the station bitrate - great if you're listening to drama or your favourite track, and need to mute the audio for some reason. You can then rewind and fast forward. If you've been listening to a station long enough, you can rewind even without pausing, too.
These functions will even work for up to 15 minutes without the key in the ignition. So if you stop for petrol, you can lock up your car to pay, then get back to right where you left off. Similar to this is picnic mode. The unit will work for an hour without the keys, so you can leave the main stereo on, leave the Highway 300Di on, open the doors, and enjoy music outside the vehicle. But you can also take the keys away to avoid pesky thieves. One thing we found the Highway 300Di didn't like, however, was removing the control unit without turning it off first, and replacing with the car already started. This made the control unit unresponsive, although leaving the vehicle off for an hour or so returned it to normal.
The Pure Highway 300Di is a specific solution for a specific problem. If you have an easily replaced single-DIN head unit, alternatives in this format with similar functionality including DAB radio can be purchased for the same or less, and will be considerably easier to fit. But if your car has a system you don't want to swap out, for a variety of reasons, the Highway 300Di does its job extremely well, and can bring your car's audio capabilities bang up to date.