im just come back from dealer for something knocking in suspension is a common problem on touring, elantra and accent 2009 and 2010 the shock boot are just press fit and with cold wheater part don't stay in place and when we hit a bump part make noise on my car 3 on 4 not snap correctly is easy to fix for rear 1 screw on each side to keep part in place and in front they just dent de side the rim

if you have something knokning in your suspention check for this