When the unit detects a car and is in “car approach” mode with the stripe down each side of the Edge 1000, that stripe is ON TOP OF the fields in the data screen. In other words, the display screen does not reformat or narrow to account for the area taken by the radar display.
Generally, this is not a problem if you have five fields or less displayed because the data in those fields is centered and does not go edge-to-edge (exception Di2 gear display). Once you have six or more fields displayed, such that there are two fields sharing the same line (one on the left, one on the right), the radar display covers up a portion of the data field, such that you won’t be able to see it.
It's kinda too bad that there can't be some options to help avoid this -- i.e. stripe down one side only, Varia info in its own data field on the Edge, etc.