I was really frustrated at the repeated crumbling of the visor clips in my '93 wagon. I have replaced them 4 times over the last 18 years. The first set of replacements lasted a long time. The second set lasted a while, but not as long. The 3rd set held up for only a few months before practically disintegrating.

So, I tried a set of black Porsche part # 944 731 439 00 instead of the white Volvo disappointments. They are a perfect fit.

So far, it's been about two years and they are still like brand new (strong and slightly flexible).
The black color doesn't bother me at all as they flank the black rear view mirror mount. They might even look better to some.
Anyway, I think they are an improvement and worth the extra cost, about $10 per pair.

Hope this helps someone else.