2002 CRV rotational sound under body at 30-45 mph
 

I have a 2002 CR-V LX 2wd bought Jan 2009, 48000 miles, good++ condition, really was one owner, literally "little old lady to church" type of driving. When accel to cruising speed around - between 30-50 and 1300 - 1800 rpm, I hear started hearing a low rotating sound from under the car - somewhere under the front - rear passenger seating. Not metal grinding more "not loud" low tone rotating parts sound. I do note that if I take the car to ~ 50 mph and take my foot off the accelerator and allow it to slowly decelerate on its own, as it passes through ~ 40 mph the sound becomes a little more pronounced although not loud metal on metal still a rotational sound. The sound not suddenly appeared but I don't recall hearing at all when I bought the car from Roush Honda Westerville OH and now "seems to be" slowly-slowly increasing. I have had careful routine maintenance at a local shop, dealer is too $$ for me, and make sure that fluids and grease is all done properly each time on time. Especially last time I told the mechanic and he didn't find anything wrong.