Well, Wetsounds got back to me and the faceplate for the integrated 420BT is 1 5/8" x 8" which means that it's smaller in height than a standard DIN sized opening (height on DIN from what I have found online is 2.11" and the DIN width is 7.2"

Thanks a lot wetsounds for making something that doesn't fit a standardized size. Lack of foresight if you ask me.