I had originally posted this in the detailing forum, but it doesn't seem to get much action, so I've reposted it herein. Any advice is appreciated...

Does anyone know of a good, reliable, and perhaps somewhat discrete means of stopping a crack in the dash before it gets too far along? Starting at the back right corner of my left front speaker grille I have a crack in the dash that is currently less than an inch long. I have seen various "dash repair" products around. Are some better than others?

Thanks,
-Ken
1984 300SD