Aage
I drove the Balkans in June 2015. Slovenia, Croatia, Bosnia, Albania, Montenegro, Macedonia, Bulgaria & Greece from the UK in my 1980 +8, a 6500KMs round trip. There was an article in Miscellany later that year.
Croatia we stuck to the coast road which was really scenic with smooth roads. I would try and make it to the Croatian islands in the Adriatic. We stayed at the Hotel Esplanade in Crikvenica and Hotel Life in Rogoznica. Montenegro is also worth visiting if time permits.
Regards
Stephen