There are not many of those left that use 100% PAO/ester stock (at least in oils designed for modern passenger cars). Why does it matter to you so long as an oil still has substantial PAO/ester, but also has some Group III?
With new car drive-train warranties getting longer each year (Hyundai, GM, and others now offering 10-year drive-train warranties) you must change your oil at least every 5000-7500 miles, so 100% PAO/ester is not economical.
It would be useful to know which synthetics (like Castrol Syntec) are probably 100% Group III.