Bug when resuming music on car stereo

Hey all.

Something has come up of late on my iPhone 5 running 6.1

Normally the music app will always remember what song I was playing etc. But lately whenever I plug my phone into my car stereo via usb cable (Clarion CZ501a and later CZ702a), the music app doesn't start but music does start playing (not sure if this is how it should work or not).

The annoying thing is that it will always start playing in alphabetical order from the very start of my library, even if I was listening to music 2 seconds before I plugged it in to the stereo. This happens I would say 9/10 times

I would like to point out that it wasn't changing the stereo that made the problem appear. It started happening out of the blue about a week before I changed the stereo. I haven't changed any settings in my phone knowingly and the stereo has what is called "Simple Mode" which lets you control the music via phone instead of through the stereo (a feature implemented in 6.1 anyway)

Things I have tried:

Restoring my phone

Using a different cable (sometimes use an official lightning cable, sometimes use an ebay lightning/30 pin 2-in-1 cable)

Changing the stereo (nothing was wrong with the CZ501a, I just wanted rear usb)

Wiping all music and resyncing it

Plugging the phone in with the stereos "Simple Mode" OFF and ON

I am out of ideas and it is starting to drive me mad. Any help would be greatly appreciated.

Cheers

Shane