Interesting...Tejas chapter of BMW CCA drives these roads all the time. If you want som REAL Hill Country roads, come on down west of SA along I-10 and get on Ranch Roads 335, 336, and 337 around the towns of Bandera, Leakey, Medina, Uvalde, etc. Some areas have 1,000-ft dropoffs on the outside of the curve and a solid 100-ft high cliff on the inside. Makes for some breathtaking moments, especially if there's traffic coming the other way.
But if you want to stay in that general area around Austin, try the roads that wind through the Balcones Canyonlands out between Lago Vista, Marble Falls, and Burnet...they're a lot more interesting than Lime Creek and 2222.
2013 F30 335i M-Sport 8AT/MPE/MPPK, 2016 228i M-Sport Cabrio 8AT