Technical Squeaky car when driving very slowly in traffic??

[Nuforce]

I continue to try and iron out all the niggles with my wife's new to her 2014 1.2 500C.

Next issue is a squeak. It starts happening after around 20 minutes of driving and it sounds like squeaky brakea but is happens when trundling in traffic with no pressure applied to the brakes. The noise doesn't change or get worse when brakes touched either.

Any ideas what it is??