I just spent two weeks on a drive through France, Switzerland, Italy, Czech
Republic, Germany and Belgium. While I brought some emergency cash and
travelers checks which I did not expect to use (and did not), I used Visa
nearly everywhere and ATM's for the little cash that I needed for tips and
tolls. In the case of tolls, most of the booths also accept Visa. I hit the
ATM for only $300 in total and I still have about $30 of Czech Korunas left.
One stop in Austria did not take plastic, but it did take almost any
currency and I dumped my lira there.