I have searched on this topic but couldn't find this problem specifically so apologies in advance if it has already been addressed.

I have an 04 6mt (Bembros) and I've got a strange squeaking problem. The brakes don't squeak at all when I stop (well...once in a great while but that is ok). What they do is squeak after I have been driving at highway speeds for awhile. I'll be on the highway...no problem...come to an area where I have to slow down to say 35mph and then the brakes (sounds like the rears) start to squeak...not real bad but enough that I can hear them with the windows up if the radio is off. If I just touch the pedal it stops but as soon as I let off it comes right back. It doesn seem to happen unless I drive at highway speeds for more than 30 minutes?

Any idea what the heck is going on?