Well, it doesn't have the icon of an application yet (we all see the same blank icon) but if you select the menu item Finder > Preferences, click on the Advanced tab and check "Show all file extensions", you should see that it's actually called carview.app.
Also, if you select carview and press Cmd-i, you should see in the General tab of the Info window that Kind says "Application".
If this is the case and it keeps asking your for an application when you double-click it, there's something fishy somewhere. It might be that the archive wasn't expanded properly (hence my previous question about Show Package Contents, info.plist, etc) or it could be your system.