Okay so, I'm at a light with the brake pedal depresed, light turns green, when I take my foot off the brake and befor i touch the gas i hear/feel at "thud". Not a huge noise, but noticable. My mechanic tells me it's play between the driveshaft and the rear end. Says it's common. Any ideas from you guys? Any common/cheap-ish remedies? Is it gonna tear something up? What to do? Thanks for the help.