anyone got a dump pipe for a au?

I assume you are talking a diff dump pipe for a NA car and not a dump pipe used in turbo applications?

If your after a diff dumper, take the car to an exhause shop, get then to cut your system at the diff so it dumps as it comes back down from going over the top. get then to cut on a straight section, then get them to sleve the section they cut off so you can reinstall it later if you feel the need.

Can I ask why do you want a diff dumper? rear muffler rusted out?

sorry i was after a dump pipe for a turbo

I'd say get one made - there are going to be too many variables in getting one to fit 'exactly'.

What turbo are you running ? What size is your exhaust housing ? Is the turbo manifold low or high mount ? What type / size flange on your exhaust / cat ?

By the time you bought a second handy and got it modified to suit, you would be better off having got a complete one made up IMHO.