Sony Xperia Z1S and Toyota C bluetooth connection problem

I have a few questions.

I have a stock Prius C audio suite - it's not entune, it's the thing that looks like a gameboy and has basic digital displays - what is the name of it? MY first question is: is there anyway to replace this with Entune or another comparable deck? I quite hate it.

My 2nd question is about the bluetooth. For about 5 months my phone (an xperia z1s) synced perfectly fine when I started my car up to the car's bluetooth. After the latest android update there is now a 25-30% chance that it won't connect no matter what. I have to delete the phone from the car, and I have to unpair the car from the phone, then put it into BT pairing mode and resync. It is a giant pain in the nice person and part of the reason why im looking to replace the deck - as per my first question.

I usually use Sony's walkman app to play music. Usually it would automatically start playing as soon as I started the car. If I wanted to I could pause it, then switch to pandora.

Now it seems that there's a chance it won't connect, and if it doesn't, I have to do the above steps. IT also seems that if I turn off the car while pandora is connected it will make this extremely annoying chop noise every 3-4 seconds of the song that I was playing, like half a second of the song. Halp.