I bought myself an older car with no auxiliary input. In my previous car I used a tape cassette adapter plugged into my phone. This is way easier and quieter. Start the car, plug the thing in. You only have to set the station and pair it to your phone the first time, after that it’s automatic, you just have to tap play on your phone. Your phone doesn’t have to be plugged in but there is a USB slot so you can charge your phone through it if needed. Really convenient and no downsides other than you have to unplug it when the car’s not running to avoid draining the battery, and there could be radio interference if you choose a frequency that someone else is using, but it’s easy enough to change. If you want to get creeped out, leave it plugged in but don’t start the music on your phone and just wait for it to pick up staticky music or voices from who-knows-where (nearby cars using similar devices, probably).