Help with Itinerary and Ferry Transportation

I think the car ferries to both Brac and Korcula leave from Split so there will be a bit of backtracking in your plan. It looks like tickets aren’t available yet but you can see the schedule from last year and the travelling times online. Based on that I’d be happy to book accommodation especially as you are out of peak season.

Google maps shows the car ferry routes so you can put in your destinations and get a basic route outline that way.

I’m also planning a Croatia road trip for next summer so have been looking at this a little bit.

To get an overview about car ferry routes check out following link.
https://www.jadrolinija.hr/en/sailing-schedule/local-lines-2023
Most car ferries are operated by Jadrolinija. Click on the maps for Rijeka, Zadar and Split area to see possible ferry routes.
Schedules for 2024 are not published yet, but typically there are not many changes year over year.

Leaving Mali Losinj you could use ferry line 401 to Zadar. In pre-season it runs twice a week only.
I used it once in the other direction (from Zadar to Mali Losinj) It’s a long journey (6-7 hours) because main reason for this line is to connect the islands Ist, Olib, Silba and Premuda with the mainland. But it was also a beautiful relaxing journey including the sight of some dolphins and approaching Mali Losinj by boat is just magnificent.
Thus, going by car via Cres (short ferry Merga – Valbiska), Krk and the Krk bridge would be the faster option, specifically if you plan to include Plitvice lakes on your route.

We are in the initial phase of planning a 7-day trip to the Croatian islands. Initially, I thought we would travel from Split to Vis to Hvar to Brac and finish in Split. After some research on the Croatia Ferry website it seems it is possible to do this- but without a car. If traveling with a car, you would need to return to Split in between each island visit. We visited Hvar with a car in 2019, and I believe having a car allowed for a lot more adventures on the island. Does anyone have experience with car rental on the islands?

I don't know when your 7 -day trip is occurring, but the ferry schedule for May, our trip, is not yet published. A link to the 2023 ferry schedule was provided earlier in this thread and might help you plan. We plan on renting a car the day we leave Zagreb and keeping it until our last stop in Dobrovnik. I'm still trying to figure out the mid part of our trip which hopefully involves a visit visit to Brac and Korcula islands. We may just end up doing a day trip to Brac from Split (leaving our car there, but, again I have to check what the ferry (car) and catamaran (no car) schedules look like. I just haven't had a chance the past few days, but hope to figure it out this week.

I'm keeping an eye on this thread for helpful bits of advice based on experience. :)