How SEARCH works
When you are on an individual bimmerpost site such as ZPost or M3Post when you click the search button it will only search the forums related to that specific site. The general BimmerPost forums such as off-topic, this forum and the general BMW forums do not get searched. This is done to keep the clutter from off-topic threads out of search results to give you a better result. However you can also search those forums by clicking on the "Bimmerpost Universal Forums" Header and then click "Search this forum" at the top right and that way search inside the offtopic/etc areas.