Fit your aftermarket head unit to the faceplate frame of the installation kit.

Depending on whether you have a 1DIN or 2DIN unit, this might mean some extra work.

The installation kit faceplate frame has some room between the sideplates and the actual device frame.

Also, using a 1DIN frame did not provide enough support to not fit without the sideplates. Perhaps when installing a 2DIN device with this faceplate, no sideplates are needed for support.