grill block sealing question
 

I was wondering do grill blocks have to be completly sealed? I fitted a grill block to the lower grill in my 206. The grill intake is recessed into the bumper so I cut a section of plexiglass to fit into the recess, there is a gap of around 1-3mm around the grill block.

Does this air still get deflected round the car or does it just force it’s way through the smaller gap?

That small gap is not going to matter very much at all. As you describe it, that is smaller than some of the other gaps in the front, such as around the headlights. You probably need a small amount of air flow through the radiator anyway.