Sync and bluetooth

Probably been asked before but I'd like an answer directed at me personally if possible :)

I'm trying to use Google Assistant on my phone when connected to the car. Don't get me wrong, syncs voice dialing is ok but I can't search for, say the doctors surgery opening hours etc and I'd like to be able to.

First step for me was to find a way to turn GA on only in the car as I don't want it listening all the time for me to say 'ok google' and draining the battery.

Managed that with Tasker so that's fine.

But then I realised that while the phone is connected to the cars Bluetooth, it switches off its internal mic and can't hear me saying "ok Google"...

And of course the cars mic only works when I press the voice button and sync doesnt pass the audio through the the phone unless a phonecall is being made.

I don't really want to use an app to force the phone to use its mic all the time on Bluetooth as this would make calls less audible for the other person to hear me.

What I have read is that Sync (or a version of it) is able to pass-thru a command to the phone after you press the voice button by saying something like "device command", or so I read somewhere.

Question time.

Is this true and if so, what version of sync does it apply to? I have a 2014 focus with navigation, non touch colour display and the button on the wheel that looks like a person talking, I think I'm right in saying this is Sync 1.1?

Finally, if I don't have the right version of sync for what I want to do, is it possible to update, or is it the hardware that would need updating (to the touchscreen jobby)?

Many thanks