Plitvice visit between 2 drives

Sure Plitvice is "doable" between long drives, but you'll probably feel rushed in the park. I'd personally feel anxiety about driving to Split (though the drive itself is pretty easy), dropping the car at the airport, getting a bus or taxi into town, then finding the hotel - don't want to check-in too late, want to eat dinner, etc. It's a shame, because Plitvice is one amazing place.

Personally, I was a little disappointed in Split, especially after the way Rick kind of talks it up in his book as some sort of cosmopolitan gem, which I didn't quite think it was. I can understand with the ferry option that logistically one night may not be quite enough. If there's indeed a ferry or catamaran leaving in the morning then you might want two nights in Split (to maximize time in Hvar), but if you'll be taking an afternoon catamaran to Hvar, you could probably get away with one night in Split in my opinion: arrive noonish first day after Plitvice, spend afternoon and next morning before heading to Hvar. Many find a stroll along the Riva and a tour of Diocletian's Palace sufficient to get the gist of Split. Even if you like Split better than I did, I highly doubt it will turn out to be your trip's highlight, whereas there's a chance Plitvice might (it was for me).

Buy some car snacks in advance in Rovinj, to fortify you during the long day, and do plan to start driving early. Check how late the airport car rental office is open, and alert the Split hotel that you'll be arriving late. For instance, it looks like Europcar at Split airport is open late, but charges an extra fee between 20:01 and 23:59.

It may be too late but if you can try to spend the night in the park. We got there late in the afternoon and there were very few people. The next day about 10 or so the tour buses moved in and the experience was not nearly as enjoyable. I'll echo what someone else said--I didn't find Split to be that good. Granted I didn't see it all but I was ready to move on. Plitvice is to enjoyed slowly if possible (we visited in May). Didn't got to Rovinj so I can't speak to the city. Bled is great. Spent 3 nights there. Mostar was a good culture shock but a long day trip (we spent the night)!! Montenegro was ok and a good day trip --but you should check it out. we spent 3 nights in Dubrovnik and I didn't feel rushed. Best of luck!