Joying Rk3188 Head unit Questions

I've tried searching and couldn't find any concrete answers (probably tapatalks fault) to the following problems. What is the voltage on the audio preouts(RCA's)? I just installed the JY version yesterday and noticed my volume has greatly decreased from the OEM unit with an active Line out converter. I'm thinking its the preouts voltage. The second question has anyone been successful at getting torque or Carista to work? I have a BT ELM 327 adapter that I've had for years and it has worked with all other android with out a problem. It does not even show up in Bluetooth devices. The third question is on cars with a can-bus system. I have this installed in as 2011 VW CC, is there anyway to get song information to show up with a music app other than the stock music player? I'm not too fond of the JY music interface. I'm currently running Malaysk's ROM and darkleo's MCU v2.59

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