I realize there is a current thread going on this subject, but I want to know specifically where to install the sound deadening.

For starters most all of So.Cal's freeways are concreted, but there are the occasional patches of asphalt.

I've felt that I had bad air leaks coming from the side windows and adjusted them. Nothing changed. Then when I drove over about a 200' long patch of asphalt, the 'wind' noise went away. then came back immediately after returning to concrete.

Back, to the question, where best to install sound deadening to alleviate the concrete tire noise? I'm pretty sure that the majority is coming from the rear tires.

If someone here has resolved the noise issue - specifically - for driving on concrete roads, please reply.

I'd also be curious as to know what the majority of surface you drive on - and the approximate noise level of your interior - assuming with a stock exhaust. I would imagine that some tires are quieter for this application, so that might also be good info.