rattling noise from somewhere aghhhh

[mrvillicus]

Ive had a rattle for a while now, today I changed the cat and link pipe as I believed that was causing the rattle as the cat spring had snapped and it did make a noise. However after changing it the bloody noise is still there The noise sounds metallic, it only appears when I go over bumps etc. I have checked all of the heatshield, the rear exhaust section and to me they seem fine. I used a private road a few times that is absolutely terrible and really does bang the car about and the noise seems to of ocurred since using that road as when I bought the car and didnt use the road the noise was not there.

Has anyone got any ideas what this may be? Its embarrassing going down a road sounding like im dragging tin cans with me