I've been looking for a mod that gives the option to have the PC's face scarred, but can't seem to find any. Am I not looking hard enough or are there not many (or any at all)?

Saw one on the Nexus forums before I quit. Search "Dueling Scars" in their request forum, you'll find it. By a fellow named Yamcakes, unless I misremember.

Damn. the file got deleted.

Django's Unique Features will add facial scars, tats, zits, warts, etc to every NPC.
You can also change your Player's features by changing the age slider in the character gen screen.

I don't really want things on NPC's, just a scar or two on my PC.

In that case a custom race would be required I think. However http://www.tesnexus.com/downloads/file.php?id=8261 is easily customisable by simply deleting the variations you don't want (.dds files). If you only installed the scar(s) you wanted on the race you plan to use, the chances of meeting another NPC with that scar would be slim.

I seem to remember you asking about Khajiit improvements in another thread. Django's Khajiit features work really well with Slof's textures and add nice variation to Khajiit NPC's. This, and some scars, is the only part of Djangos Unique Features that I actually use.

Thanks.