2 Day Rental?? might need more....
SERIOUSLY....Texas is BIG....even the area around Austin. My suggestion.... Get a Butler Texas Hill Country Map(I'm a dealer...nudge nudge) ....Ride as many of the really fun little paved "goatpaths" as possible in your time available. (there are plenty shown on the map!!) Don't forget a pic at Oatmeal Tx!!
Stop at the store in Castell west of Llano(beats the line at Coopers!)....On weekends they have BBQ or steaks (check before ya go though) Maybe the chicken is still there doin it's thing. Interesting place?!
The whole area around Fredericksburg is covered with those "goatpaths" & Luckenbach is closeby. There's also an old railroad tunnel with bats if you're into that. (or the Congress Ave bridge in Austin too)
The really big hills (3 sisters) are farther away & the roads get super crowded on weekends. Weekdays are the only time to ride em.
Just remember when riding the roads on the Butler map....the further west you stay away from I35....the better traffic wise. Generally close to or west of US281
ThThThTHHhats all folks