Rattle, Rattle, ARGH!!!

[aspullite]

I have a Fiesta Zetec S 2001 and I recently had my rear bushes changed and ever since I have had a rattle from the drivers side rear. It sounds like a plasticky type rattle as though it is interior but I cannot find it and I have pretty much stripped the rear of the car!

I took the car back to the garage, who did the bushes, to let them check it over to see if they had moved something and not put it back and they said the drivers side top mount had perished. They changed it (£60 thank you please) and said it was sorted. As soon as I picked the car and drove home, rattle, rattle, still there.

So far I have:

checked inside the arch
taken the rear door cards off
checked the rear seats on the catches
checked the speakers
checked the boot
zip tied the handbrake cable down
removed the jack

and still it rattles.

I have pretty much run out of ideas and, as i like to drive around without the stereo on quite a bit, it is really annoying.

I am reluctant to go back to the garage cause they will probably try and get some more cash out of me so has anybody got any ideas what it could be.

Cheers.