If you don't have a pull out canopy or similar, I would recommend getting something like this
http://www.decathlon.co.uk/tarp-camping ... 63223.html. I managed to get two for a tenner each a couple of years ago. No good in a storm, but will help keep the light rain off, and more importantly, the sun. We do a 3 week drive through Europe every year, and this has been one of the most versatile items in our kit. Packs down very small and lightweight, and can be erected in a number of different ways. I usually attach one edge to the brackets under the raised roof, using some clever self-clamping bungees that I have (clamps around the fabric and holds it very firmly indeed). Under that, we cook in the evenings. I also have a proper, heavier weight canopy, but never bother taking it, as weight and space are at a premium.
As Muz says, organization before the holiday is vital, but we don't bother booking camp sites before we go. Even in August, we have only ever been turned away from a site twice in 7 years, and even then, there was another site just down the road.
We usually pick our camp sites from the ACSI guide, and have always found them to be good. You can download an app now, for phones or tablet, which lists the ACSI sites in specific countries or regions, and includes reviews. These can be read offline, so no data charges. Each region costs a couple of quid or so to download, though. If we don't know an area, we look at the map in the ACSI guide and look for a cluster of camp sites. If there's several camp sites in an area, there's usually
something worth seeing!
Make sure you have enough cash - some campsites only accept cash. Also, its worth getting a camping carnet card. Some sites demand to see, and sometimes retain your passports during your stay. With a carnet card, you hand it over instead of your passport; much better. And speaking of security, we use a small travel safe to hold some documents and small items. Not foolproof, but enough to dissuade the opportunist - you can't carry everything around with you all the time, and its a good idea to split your money.
We often get trouble with both debit and credit cards, especially in France and Belgium at self-service/payment-automated petrol stations. We've also had a problem at toll booths on a couple of occasions. So again, its good to have enough cash.
Think carefully about your cooking equipment before you go. I manage to last a full 3 weeks on a full bottle of Campingaz 907, and have plenty left over at the end. A 904 would probably do us. Campingaz is supposed to be easy to get hold off in Europe, though I have never needed to. I understand you would have difficulty getting hold of Calor. Campingaz is hellishly expensive over here for what it is. The last two years, we have left the Campingaz behind and used 227gram CP250 cartridges instead. You can pick these up for less than a pound each, and on average we use less than one a day. Carrying around 20 gas cartridges doesn't really take up any more room, and are much easier to stow, than a bulky Campingaz cylinder, and of course, you have less of them as time goes on. The cookers for these you can pick up for less than a tenner.
Be aware that you cannot take a diesel Bongo into some cities, especially in Germany. There are websites showing the relevant cities. We usually camp outside of the cites anyway, and take public transport in.
May also be worthwhile getting a blue parking disc before you leave. In many places in Europe there are parking restrictions where you have to show the time of arrival and leave within an hour or two. A blue disc is mandatory in such places. You can get them via ebay, or pick one up in a shop over there.
