Posted on 19 Oct 2013
Maybe I should just add to my rather hurried answer late last night!
You don't say how you will be visiting the continent, motorhome or trailer caravan?
If you're in a motorhome then the stelplatz in Germany and the aires de service in France offer a great place for the camper on the move to spend a night or two. They are often free with a small charge for services in some, particularly electric hook-up and they are often in really nice locations, not stuck out on the industrial estate or some less desirable part of town as I could imagine them being in Britain if we were to have any! There are books showing all the stelplatz and aires and these can be easily purchased on the internet.
France also has a rather more relaxed attitude to motorhomes than the UK and as long as you're not being a nuisance to anyone, wild camping is widely accepted. You would of course need to be pretty well self-contained to do this.
As well as the free alternatives I've mentioned, you would do well to look into staying at vineyards. We stayed at one in the Black Forest. It was a pleasant place in a village and in exchange for eating in their extremely reasonable and very tasty restaurant we stayed for free, even including electric hook-up.
Another possibility in France is the 'Camping Municipal', usually a little more basic than commercially run sites but still good and with all that you need to stay.We also used a similar site outside of Freiburg, Germany. It was very reasonably priced and within easy walking distance of a good tram service into the town.
Add to that the fact that, at present, diesel prices are slightly more favorable on the continent, due in part to the exchange rate, but do fill up at the supermarket gas stations, and you have the makings of a really good trip at reasonable cost. I would second what has been said about the friendly welcome there is to be had in both countries and if you speak even a little of the languages it will be much appreciated.