thank you for this post!
I got parking sensors fitted so time ago and was hoping to check this vent out back then thinking theyd take the bumper off. They didnt so i have just ignored it until i had the time, tools and better weather to do it but im glad youve said this before i attempted to remove the bumper!
I will, at some stage, have a look into this wheel arch and sort it out.
When i do get round to it i will post here to say what happened.
once again thank you for letting me know about this