My 1999 Subaru imprenza outback sport has a clunking sound coming from the back passenger tire area. It occurs when I hit a bump. It is worse in reverse. When I bounce on the back bumper I get a slight noise and the tire vibrates. I want to try to do the work myself but need an accurate diagnosis. Are we talking struts, links axel? Any feedback would be great.

Most likely struts.  Push the strut dust cover up, do you see lost of fluid?  If so the strut is shot.