My car stereo has an Aux Input that uses a standard headphone plug; I use that to route my phone/GPS/MP3 player through my speakers. It also has a USB port, but (at least on my radio) that port is power-only and cannot be used for input.
My last car lacked either, but the factory radio had a tape deck (which was a big thing back in ‘85 when the car was made) so I used a headphone-to-cassette adapter to do the same thing.
There are also short-range FM transmitters that plug into a headphone jack; tune your radio to a certain station and it will pick up the signal… though I always found the fidelity on those a bit lacking and thus only use it as a last resort.
As for drivers….
/takes deep breath
Those dongles generally only do “plug and play” with the most recent couple of versions of Windows. They may or may not be usable by Linux, and if so, may or may not require voodoo to do so. But since your car stereo probably runs neither, there likely won’t be any drivers, which may or may not be needed anyways. In fact, it’s possible that it’s a power-only USB port like mine. Or maybe it’s already set up for iOS (many stereos are set up for iPhones) and all you need is the USB-to-iPad cable like the one you use to sync it to your computer.
So, with all those bolded items of uncertainty in the previous paragraph, we are right back at the question of, “What type (make and model) of car stereo do you have?”, unless you have an Aux Input that takes a standard 3.5mm stereo plug (the same that is used on most headphones).