The sunshade (part number 90608551) is a great device for keeping sun and rain off the wind screen. I had this one on a Series 3 and it worked very well. As they are few and far between, I kept it when the Series 3 was sold.
Fitting the sunshade gave me the opportunity to try out my new riv nut tool. A riv nut is a threaded insert that allows a strong mechanical fix in a location where tapping a thread is not practical. It performs similar to a pop rivet and is basically a compression fit. You insert the riv nut, “squash it” with the tool and it leaves you with a threaded insert to screw a fixing into. If you’ve ever installed a bottle cage on a steel or aluminium bicycle frame…. the threaded hole into which you screw the bottle cage fixing is a riveting nut.