How do you remove this plastic cap above so you can access the nozzle on the saloon car?

 

Mine is cloggin again, I have to clean it. Once I removed this cap but with brute force and ended up breaking it as it can be seen.

There's a couple of internal lugs either side that clip over the gubbins that surrounds the nut.  I slide a thin blade into the hinge gap - the horizontal, upper side in the pic - and gently lever it upwards a mm or two which releases the lug.

Related topic, but how do you clean/adjust the estate version of this?

No idea either. Looks non adjustable or cleanable on my Combi.