I’ve noticed a slight whistling/whining noise from the car. To be honest I think it’s just a ‘normal’ noise but thought I’d raise it anyway. 

I only hear it at low speeds (and low revs) when I accelerate a bit. If I moved off just using the clutch there would be no noise, but if I apply a bit of throttle I can hear it. 

Anyone had anything similar?

I have something similar: 

whistling sound when pressing the accelerator.

 

Same sound both in gear or neutral. 

 

It seems to be coming from within the cabin (I cannot hear it when opening the engine).

 

I have a Skoda octavia 2016 TSI/CNG stick shift. 

 

Any ideas what it could be?

 

Another 'slight noise at speed thread' a bit lower down .

Low motorway hum at low revs

 

Thanks. But this is not a hum. It is more like a low whistle. Only when pressing the accelerator. 

I have the same. In all gears I can hear this low volume high frequency whistling sound. Most apparent in 2nd and 3rd gear at around 2,200-2,800 rpm. Holding the gas pedal very still for a while in this rpm with very little throttle makes the sound appear. Adding more throttle or releasing it the sound disappears immediately. 
I recorded the sound with the cellphone in the engine room but the sound isn’t louder there. It seems as it comes from between the engine room and the cabin, towards the passenger side. 
 

very annoying sound. Especially when driving in town where you often use low throttle and gear 2 and 3.