Neither have I, but I was pretty sure I did, until just now... Maybe I dreamt of it. Or saw it on newer restomod cars.
Warning: That's a real hackjob and probably makes them way too grippy in the rear, but at least it made the cars driveable for me. I'm on it again now, trying to make them a bit better. They actually had swappable anti-roll bars, but very limited possibilities to adjust toe and camber.
The problem, in my opinion, is Tommy's rather strange decision to use a live rear axle for these cars, which he has also equipped the BTCC Golf with. I'm by no means an expert, but using a dwb setup seems to be a better choice.
The Golf drives nicely for me, but the GTE and even more the GSi are so loose in the rear that it's borderline impossible. And not fun. A fwd car shouldn't really be that tail happy at all, unless something is really wrong.