I also suspect the guibo for your noise. My car made a rumbling/vibrating sound from being stopped up to about 50 mph. It went away at 55-65 mph. Easy to replace. Put car on jackstands, remove 8 bolts on guibo, remove 4 bolts on differential end of driveshaft, remove center bearing bolts, slide driveshaft assembly back, replace guibo, (If it has a metal band around it, DO NOT remove it until installed!!), reverse dissassembly order. Took about 1 hour. HTH