A month after buying the car used (Carfax OK) my brakes started making a
very loud groaning noise when I take my foot off the pedal from a dead
stop and I start idling forward.  I've had the brakes looked at by Nissan
3 times with them saying each time there was no problem they could see (I
was still under warranty).  Over the last 30k miles I'm now on my third
set of pads, the latest coming a month ago.  The last servicing a private
mechanic found one my rear calipers was frozen and rubbing the rotar.  I
had all 4 pads + rotars replaced as well as the 2 rear calipers.  I
thought that the problem was solved.  The brakes worked well for 3 weeks,
but now it's come back just as bad as before.  My brakes are now groaning
extremely bad as the weather gets warmer.  If anyone has any ideas I would
greatly appreciate it.  Thanks!