The existing Jensen definitely has the radio removal holes on the side of it as you mention. I have the removal tool and I actually took the radio out today from the front, just to see what was behind it and what I might be getting into. Getting the existing Jensen radio out from the front is not a problem. The problem, at least according to Crutchfield, is that the Pioneer 4200NEX has no way to be mounted from the front into the same kit that the Jensen mounts into. They claim that a different mounting kit has to be installed and the only way this kit can be installed is with the dash off.