We crossed Dover > Dunkirk and it is approx 20 hours drive time to Zadar. But, since we were on holiday we took 2 1/2 days each way and enjoyed stop overs in Germany, Austria and Slovenia.
We stuck to the motorways, though - and put up with the German trucks (too many to count!)
I for one would love to see more people sharing their adventures on the forum. IMHO this is what the Cali is really about a tool for getting out there having great experiences and having fun.