I suspect FALAGAR will chime in soon and say that it is on their TO DO or that a case has already been made to include postal code searching. I would also guess that if it is on their list, it is somewhere below improving speed and efficiency of the search engine.
Before FALAGAR can make a compelling case to move it up the priority list, you need to answer the following question:
Would you rather have postal code searching now, regardless of how slow it is, or wait till they improve the search engine?
Keep in mind that in terms of time efficiency, searching in MapSource, making a waypoint, selecting, copying and pasting said waypoint will likely be faster than a postal code search in BaseCamp 4.0.2. (Pure guess on my part).
FALAGAR, I’m not a programmer, but to me, it seemed like MapSource had two search engines. One was a proximity search (which did not use postal codes). This is the search engine/strategy that is incorporated in BaseCamp. Has Garmin given any thought to incorporating the other search engine into BaseCamp? If they have, why did they choose not to?