I just made a trip 2 weeks ago by car through Croatia. And it was more beautifull than expected. More old cities than in Greece, Old Romanian cities, cheap food, good roads, good weather, and i saw several german motor groups travelling by the coast. No problem with English, though some spoke better German. There are also some great nature parks with waterfalls more inland. Krka park, and some names i have to look up.
My route when i arrived from Holland:
http://tinyurl.com/38p5o6l
Porec, Zadar, Rabac, Trogir, Dubrovnik, Zagreb
On the way back a travelled throug Prague and stopped there for 3 days (you will like that). But you can also go to Venice in Italy. From Dubrovnik you can take a boat and go to Rome in italy.
But you have to take some days to go to Amsterdam or Barcelona. We went from Zagreb (Croatia) to Prague (8 hours) and three days later we did the rest of the route. First look if you like the country, than we can think over the route
I haven't put any pictures online yet.