Octavia, 2017.

New (to me) car. Clean it for the first time. Polishing in front of the rear wheel arch I see (my view) a paint bubble! Shock horror.
Take it to the garage only to be told that there is a segment of protective film (as I use on my smartphone glass) in that area...
And it has an air bubble in it!

   I walk away feeling a bit daft  :-) 

I know our old Roomster had a plastic film just in front of the rear wheel arch. Never quite understood why

Good question. I could understand if it were behind the back wheel, where muck is thrown up,

but in front? 

  I guess they know what they're doing...?

Just something else that's "simply clever".

actually its one of the worse areas as stones thrown up from the front wheel at speed can rattle around and bounce underneath the car and hit this area, the rear mudguard is substantial and will easily protect the area between back wheel and the exhaust. 

This is of course tested in wind-tunnel when they developed the car.

If you drive your newly washed car on a dusty road it is quite easy to see that this area need protection.

If not it would be sandblasted and free from paint after a while.

Many cars has this