[CentOS] Post postinstall configuration

I'm building kickstart files for use in doing automated installs of various systems. I would prefer to do fairly minimal amounts of work in the "%post" and postpone further installation and configuration until after the first reboot (or even later). It should be easy enough to add something to rc.local that will download scripts and run them, but I'm wondering if there is a preferred technique. I haven't found anything in the Red Hat documentation I've read so far.

This isn't about figuring out a way to do the update, it's about trying to follow the "Law Of Least Astonishment". I've dealt with too many really screwed up systems that had customised stuff everywhere and nothing worked as expected.

Suggestions?

-- Matt