When you are happy with your bend, adjust the shaft so that it sticks out of the base. You will have to rotate the shaft into place to do this. A good idea would be to group the shaft and knob so that the know stays with the shaft when you rotate it. The picture shows mine after positioning it.
Next we are going to tackle the rear-view mirror. Create a spline like the one shown in the picture. It should run from the top of the windshield to the dashboard. Make it rendereable like we did earlier on. That completes the bar that the mirror is attached to.
The mirror is simply a box. Create the box and arrange edges like shown in the picture. Select the polygon shown in red and extrude it inwards. Detach the selected polygon.