Here is Lime Creek Road linky
I likt to run to/from Bullick Hollow Road & 620 intersection
Also the drive on 1431 out to Marble Falls and Back is nice or for the shortened version go to Lago Vista and back. From Lime Creek road take Anderson Mill Road to 1431 and take a left. These spots will have some traffic and cops in the late afternoon/evening to catch drunks leaving the lake so run in the morning if you can.
I live in the area and will join you on a morning run. I've only been out a few times in the Hyundai so far pm me for my info.
Also post in the Austin thread I'm sure there will be some meets this weekend too.