Can anyone advise whether it is necessary to drop the rear sub frame to change the subframe to floorpan bushes? My 1996 Marea 1.8 saloon has developed a loud clunk under the rear seat on the offside. So far I have changed both rear springs, both rear dampers and changed the suspension arm bearings on the drivers side (the kit from shop4parts was excellent!) but the noise still remains when on bumpy roads. I understand that to drop the subframe the petrol tank must come out and this is something I want to avoid. Is there sufficient room to undo the mountings,one at a time and get the bushes out?

The bushes do not come out of the subframe. You will need to source a replacement subframe.