The item in question is a non return valve which can be carefully taken apart with a stanley blade (prise the top off). Inside is a spring and small rubber diaphragm.

My wifes BMW 3 series had her grille stolen & I watched it happen, guy pulled up on motorcycle, got off. bent down for approx 10 /15 seconds had a plastic bag on handlebars then rode off. I'd thought he'd dropped something until next morning, grill had gone. Grille only fixed on by lugs. "B...

The part is a non return valve, once you've used the washers its stops the fluid in the pipes draining back into the reservoir. You can prise the top of the valve off with a stanley blade (be very careful not to slip) then carefully remove the small spring & diaphragm. Inspect, clean the re-asse...

The side windows have 2 plastic glass holders on the bottom of the glass they are GLUED to the glass. If they become detached the glass panel will tilt. The plastic holders will have to be re glued to cure the problem. You can access these fittings through 2 holes in the metal panels. Fiddly to say ...