This is the stuff I settled on, mostly because I didn't have to buy it. I've also used it for brake caliper grease, where the pins have a rubber bushing. Seems to work fine on the latter application, I'll keep an eye on it for sunroof use. It's on the thicker side, but quieted the squeak up nicely. Appreciate all the input, I'm sure this is an application where a lot of different things will work just as well, provided the old crusty stuff is adequately cleaned off.
