CB radios with the UK band are not allowed to be taken into Europe, far less used. They can be siezed, and you will almost certainly be fined, if caught. You can even be detained over a weekend, pending a court appearance on the Monday. The aerial on the car is a dead give-away. So you need sets which are CEPT approved ONLY.
But PMR446 hand-held walky-talkies work tolerably well and are legal in the entire EU. Not as good as CB, range maybe 5Km in good conditions, which is not from inside a car, and it is illegal to mess about with the antenna.
Hand helds need a DC feed from a car adaptor to their charging stand. Everything to do that is available from Maplins.
Edit: Oh, and last time I looked, there were 40 UK channels and 40 CEPT channels. Beware of advice from people claiming to be hams who are apparently completely lacking in radio knowledge. As it happens, the CEPT FM channels are on the same frequencies as the US AM channels.
Another edit: See here: http://stakeholders....cbinfosheet.pdf
Edited by tiger99, 16 January 2014 - 11:24 PM.