I will be going thru Slovenia mid-May. Is the Julian Alps Driving tour pass mentioned in Rick's book open? Which would be better to rent a car, Ljubljana or Lake Bled? Thought about hiring a driver but it would only be me so I imagine it would be extremely expensive. Also, which is a better drive and more "wow" scenic experience, Slovenia Julian Alps or Slovakia/Poland Tatra Mountain? Thanks for any suggestions.
Mid-May should be fine. In fact, the road over Vrsic Pass is already open and it will probably remain open if there is no major snowfall or increased avalanche danger in the coming weeks.
Rent a car wherever is more convenient for you and works best with your itinerary. I haven't driven a lot in the High Tatras but if memory serves me right there are no road mountain passes in the national park.