Just wanted to thank everyone for their responses via the group and
email; I've made an appointment to have it done at the dealership, as
they'll fix it for $186 total (which sounds quite reasonable in light of
RamMan's estimate).

BTW, I might not have been clear in my original post; it wasn't just the
glass that got broken, the whole unit was smashed.  Interestingly, I
found it in several yards in front of my truck, but with no other damage
(IOW, it didn't hit my hood at all).  I was parallel parked on a
relatively narrow street, so the logical assumption is that someone in a
similarly-sized truck hit it with *their* passenger side mirror
(hopefully hard enough to at least cause them the same pain they've
given me!), but considering that the whole unit flew that far without
touching the hood makes me wonder if someone wasn't taking batting
practice ...

Best,
Ron