Gave the car a good kick in tonight, and on way back driving there was a loud sucking whistle sound, then I pulled up, revved and the sounds not there ewhile idling and revving, but was when driving, and couldn't hear when intake sucked, then drove car up street again, not there? Got a back brake clicking when hot so guessing that's disc n pads, but can that cause this sound?

Maybe rear brake? When it's hot it clicks, hotter , means louder? Binding pads or w.e?

Sounds like a turbo whistle, you don't get anywhere near the same turbo pressure when revving at standstill (engine must be under load).  Could have been a rubber pipe deformed enough to unseal itself from a union with a metal one then once you'd stopped it sealed again.  Check all your pipes to make sure they're secure.

Well all back brake drivers side cleaned up, worked a treat , all rust cleaned up on pads and carriers ect and no more whine!