Meshes are not occluding

Hi there, I'm developing a car simulator... and I'm trying to get the most out of Occlusion Culling, all I have right now are pure static objects...I've marked as occludee static everything and the ones that could occlude I marked them as Occluder static, just the way it should be, now... even though I have only static objects I'm using Automatic portal generation because it gives me the best results so far, but I've noticed that many of my Occluder objects are not occluding at all, like the image I'm showing, also the process is giving me this gigantic cells even though I have buy cell size to 1!! and also it doesn't matter if I use or not occlusion areas, could somebody help me please?

Thanks a lot, here's the image where I show how the view lines are crossing my model even though it's marked as an occluder static