HORRIBLE noise coming from the rear
So yesterday we had a local M3 meet here in TX and were out in the twisties for a while and the car was doing GREAT! After letting the cars cool and talked for bout an hour or so we took off and were heading home. The car was still runnin great until after I stopped to get somethin to drink on the way home. After gettin back in the car and gettin on the highway I noticed a hum which turned into a severe vibration coming from the rear ONLY when I let off the throttle ABOVE 40MPH. I recently got my RTAB's done but the car didn't seem to need an alignment but now it does! The car doesnt pull much but it does a little. Now I have the DSC light on,YELLOW E-brake light, and YELLOW SMG cog illuminated.
What can be wrong, is my alignment that off? It feels like some suspension compenents are loose on the rear drivers side? Any help would be appreciated.