Moshin,
I'm testing your plugin, so far so good, there are a couple of things that I would like to suggest and a conflict that I need to bring your attention to:
1. Your plugin has a conflict with the
JQuery colorbox plugin, in my case, the client's site has the JQuery color box plugin installed since he is also using Galleries in the regular posts for showcasing purposes, this is separate from the default native Colorbox functionality of CP.
2. When the user is already viewing an ad in x city, then opts to change locations to another city location, a redirect should occur listing the ads based on that new location, at this point, even if we change locations, we remain on the same ad page we were on before, so its acting as of nothing changed, the user has to click on Home or another menu to exit and browse the new location related ads, this should be dummy proof.
3. The Menu item "Select Location" should be highlighted for visual distinction, either a different font color or cropped back-ground color, ultimately a separate insertion under the main menu (right-side) or a widget like approach would be nice.