It is my audio system. I've done a few different versions, first being a bluetooth receiver out to audio controller to split into front/rear/sub didn't sound great though. (this setup was about 200 bucks) My current setup is an Apple Airport Express, optical audio out to a audio processor > out to amp > out to speakers. Airport express sounds awesome but requires manually connecting to it every time you get in the vehicle. I had to tweak some setting on the wifi setup on the iPad so it continues to use cellular data when connected to airport wifi.
Parts list:
Airport Express - Was my router previously which was replaced. - 70 bucks used (100 bucks new?)
3 ft. Optical Audio cable - 10 bucks
Soundstream Harmony Digital signal processor - 150 used (I think 250 new)
Kenwood KAC-M1804 4 channel amp x 2 - 85 each.
12v to 3.3 v converter to power airport express. I think it was less than 10 bucks.
I already had a blue sea fuse panel and breaker at battery which I would recommend for anyone adding a bunch of powered devices. So those may be an additional cost of you don't already have them installed.
If you already have an iPad mini that saves to, if you are buying one just for your car head unit that's the big expense. I use mine everyday outside of being used in vehicle and I owned it before adding into vehicle.
I 3D printed my own bezel to hold the iPad mini so that saves too. They can cost upward of 300 bucks just for that piece before it's even installed.
So as with most things, if you do it yourself and shop around it can be done without spending a ton. I think my costs were probably a little less than a high dollar double din head unit and I'm pretty sure I have more features available to me with the iPad and sound quality is awesome.
I've seen the magnetic mounts that you can stick somewhere on your dash or the windshield mount or the floor mount, tons of cheap options. I just did molded into dash because I could.
