The clip where June starts the car is if anyone wants another look at it, although it's not the best quality clip.
It's hard to tell but June starts the car and there's no noise from the radio, then a bit of static and we see her hand on the dial and then the voice comes through.
So it could have already been tuned to that station but not working well because she's in the garage, or it could be that she got very lucky finding that particular station first as soon as she started to search.
There aren't any spoilers in the clip but be careful on YouTube anyway in case the following clips are for future episodes.