How you mount your dashcam is critical to collecting quality video footage. The better the video footage you collect the better the map. The better the map, the better the rewards for contributors. It may take a few extra minutes to get it right, but since contributors drive for hours upon hours it is well worth the additional effort.
Bad dashcam mounting examples
Too much car roof
This is a fairly common problem, and is easily addressed by tilting the camera upwards a bit so that less of the car roof is in the frame.
Interior - front facing with too much hood
Vehicle interior visible in the image
If the footage contains any aspect of the vehicle's interior that is not going to produce a quality image for the map. Below you can see in the bottom corners one can see the vehicle's dashboard.
Interior - front facing with vehicle dashboard visible
Use dark cloth or t-shirts on your dashboard to reduce reflection from the window. It's a little hacky but it works.
Exterior front facing
Dashcam pitched too far down.
Exterior - front facing with car hood
Exterior side facing at traffic
The camera is pointed at traffic side, rather than pointing at the sidewalk and buildings. For example, if you are driving in the United States, to fix this issue you would need to mount the camera on the right hand side.