Remembering my old 95 900 SE... If I crossed the SF Bay on windy days, this thing would dance all over the place. I had to slow down. Almost as bad as an 86 Mazda RX-7 that I once owned (that one was the worst ever in cross wind).
The 2000 9-3 SE seems to be significantly more stable, probably thanks to its rear spoiler. But the front spoiler and skirts might contribute to the improvement.
I would expect the Viggen to be a little more stable, yet.
The most stable car I've ever driven was a Porsche 928 S4. If you feel any cross wind in that one, you are simply going too slow. Once you hit 90mph you won't feel any of it.
Of course you can only do this on a race track, right? :evil: