Boa Man5

I've been trying to search around and find info on what it would take to upgrade the Sony amp for the door speakers? I can't find specific info for a non-nav Sony set up, especially with inputs to the stock amp. Is ther a PAC module for this system? What would I lose if I swapped it out? there's no GPS, so that's not a concern, but would it affect my phone calls?

Thanks for any help y'all can provide.