Hey, I searched for an answer to this in the archives and didn't find it - apologies if I missed one that's already there:
I have a '13 WRX, stock HU. I paired my phone with the HU no problem - BUT every time i get in the car, I have to manually connect the phone (either on the phone or on the HU). It never pairs automatically. Default when i start it up is to say "NO DEVICE". I let it sit for more than 10 mins just to be sure it wasn't a lag thing. Once I pair it manually, it works fine (voice and music).
I get the same problem with different phone mfrs. and OSes (had a Windows Phone earlier, now iPhone 5). Any suggestions?