Darken the VW emblem in the front of the Facelift?,

[DarrenW]

It's best not to modify the radar fascia.
It's engineered for optimal radar attenuation. Any modification will almost certainly degrade performance.

[Gaz W]

My advice would be to leave it as it is,

ACC sensors can be problematic at the best of times and are easily affected by outside conditions weather, dirt and mis-alignment and is a costly out of warranty fix to carry out replacement and calibration processes!

[fredgroves]

Try a black marker pen?

[Wide]

Try a black marker pen?

  Yes that is on my mind now..