mk3 golf gti anti-roll bars

[lankylari]

Do mk3 golf gti 8v 3drs have rear anti roll bars? if not is there a mod to fit one?

[harlemex]

I think there is one in the rear swinging arm.

[Len]

Do mk3 golf gti 8v 3drs have rear anti roll bars? if not is there a mod to fit one?

Yes

[tweed]

in the rear beam 

have a good look and you will see it

[lankylari]

cheers all had a look today when fitting coil-overs.  how can I change this for a bigger one! as it goes in side the rear beam?

[Ess_Three]

cheers all had a look today when fitting coil-overs.  how can I change this for a bigger one! as it goes in side the rear beam?

You can't...
The aftermarket rear ARBs bolt externally to the beam and damper bolts, or bolt through the U section of the beam on some of the more specialist designs.

In either case, it's an additional rear ARB that works along with the standard rear ARB...the front ARB is a relpacement part.