Hello, please critic our itinerary. Is this doable? Tips/advice/anything we need to know? We have roughly 25 days give or take.

• We'll flying in and out out Budapest and renting a car picking up and dropping off in Budapest.
• We don't like to drive more than 5 hours in 1 shot.
• We generally like 3 nights in one place and not want to rush too much.
• According to google maps, are these driving times accurate?

1. Budapest - 3 nights (pickup rental car after check out)
2. Ljubljana - 3 nights, 4 hr 28 min(463 km)
3. Lake Bled - 3 nights, 45 mins (We just wanted to chill in Lake Bled)
4. Plitvice Lakes National Park - 2 nights, 3 hr 30 min(261 km)
5. Split - 3 nights, 3 hr 10 min(275 km)
6. Dubrovnik- 3 nights, 2 hr 58 min(233 km)
7. Kotor - 3 nights, 2 hr 2 min(92.3 km)
8. Sarajevo - 3 nights, 4 hr 44 min(263 km)
9. Osijek - 1 night (cut down the long drive), 3 hr 48 min(285 km)
10. Budapest - 1 night before flying home, 2 hr 51 min(264 km)

It depends on your interests! For me, I'd want more time in Budapest and Split. More to the point, I'm surprised by all the places you are skipping, most notably Mostar, Croatia's stunning islands, Istria, Zagreb.... Personally, even though I love Budapest, I'd hold off on Budapest to make more time for the rest of the region... YMMV. I'm sure you'll see some wonderful things no matter what you decide.

summer or winter, perhaps a month please. I'd not do this in winter

If you like to drive fast and, if possible on motorways, and if you don't like intermediate stops, but prefer to bypass all gems along the itinerary, the times you indicate may be possible.

The OP's other thread indicates a plan to begin in September. I'm assuming that remains the case, but could be wrong!

When I see plans that include timings like '4 hr 28 min' and '2 hr 2 min' I assume you looked at googlemap and copied the drive times exactly via the fastest route. Those times will almost never be accurate on the day. Factoring in traffic, photo op stops, petrol stops, etc you can add 10% to 25% to most drive times . . . and a lot more if you choose the more scenic routes.

Just a note that driving in Slovenia needs a vignette before you drive on any motorways, and an IDP is mandated. You may not be asked for it ever but it is a legal requirement.
You need to check if any of the other countries you plan to visit requires a vignette , and where to buy one too.

Why not stay longer in Bled and visit Ljubljana from there? That will give you a couple of days to either see more of Slovenia, or some of the other places you will rush past.

Google aps etc always give the fasted route, even if you switch off the motorway option. It doesn't give you the best/most scenic/interesting route. A map is very useful on any road trip.

janisj has made a very good point! And if you are using google maps (or other mapping function), be sure to adjust the times. If planning in N. America, for example, you often end up with estimates of driving times in the middle of the night in that part of Europe, which don't reflect daytime driving times at all! And you should map from hotel to hotel (or other lodging) -- estimates based on city designations can be substantially off. I'd rather get somewhere early than late, so I adjust the time, use actual starting and ending points, and then add at least 25% -- time for unexpected events, heavy traffic, stopping for gas, etc.

hetismij2's suggestion to stay in Bled and visit Ljubljiana from there might make sense, though I must add that I am truly glad I had time in charming Ljubljana during the evenings.

I have found viamichelin.com more accurate for estimating driving times in Europe than google maps. Google seemed to underestimate the driving times by a fair amount.

Also, don't discount border crossings into Bosnia and Montenegro as well. Border traffic will be a factor in September and your time in the car potentially increased.

Also, any driving around Bay of Kotor might not be reflected in online driving sources. It is a one lane highway both directions and traffic is a factor.

I personally would find all the time you have planned driving to be too much for my tastes. YMMV, obviously.

I agree that Budapest is the outlier here. consider starting and ending in Zagreb, or Ljubljana.

I think I’d go out of my mind with boredom with three nights in Bled. It’s so touristy there. Ljubljana has so much going for it, super fun and vibrant in the evenings, try to be there on Friday for Open Kitchen (odprtakuhna.si/en/) and Saturday for market day. If you just want to chill by a lake, there is also Lake Bohinj.

Do try to fit Mostar into the mix - it will help with your driving times - and visit one of the islands, even if just on a day trip from Split without your car.

Yes, correct Sept next year.

We'll be in Budapest for sure (before that Vienna). But we'll look into Havar and Morstar. Thanks!

Thank you all for your replies!

If you rent a car, the car rental company will ask you if you plan on driving in any other countries and which ones. Not all possibilities are allowed. They will charge you for each country, and that charge will include the vignette you need to legally drive in that country.

Things must have changed since the last time I rented a car in the area, when it was up to me to know that I would need a vignette and to purchase it. Granted, it's been a while, but I was glad that I had been advised to look into it.

In Slovenia you need to buy the vignette as soon as you cross the border. If you rent the car IN Slovenia them the car should have their vignette. Don’t forget about this vignette - fees for not having it are very high.

You do need to tell the rental agency where you plan to bring the car, and if you plan on bringing it on to any island.