MY99 UK Turbo. Just removed my standard exhaust. There is no gasket between the back box and the centre pipe. Also, between the centre pipe and the downpipe there appears to be no gaskets. There is a flange fitment between these pipes due to the fact they are held in place by spring bolts. Is there meant to be gaskets or not?

There should be gaskets on both, the rear one is not majorly (sp) important but the DP to centre is.
However.... You will find that the DP to centre gaskets is there, its just that it looks like part of the downpipe. Hav ea good look at the Downpipe end, you can just make out that there is a mesh gasket on the end of it. It is a solid/mesh gasket that slots over the end of the downpipe to make it round - to slot into the centre section flange.

Rob