In reply to An Triubhas:
It depends where from, exactly where to, and how many people.
I always reckon on two people being about break even for Bavaria to southern England by car. It's a tank of diesel (1000 km) each way, plus about €90 for the ferry (dover-dunkirk). More people than that and driving becomes even cheaper, fewer, (i.e. 1 person) and driving becomes more expensive. That's all without hiring a car. If you want to drive around a bit at your destination (for example if you want to drive from the airport to your destination), then driving is definitely more sensible.
However, if you are driving to Cham or somewhere in France, you might have to consider the peages, which could make difference. Personally, I like the flexibility that having a car gives, so would tend to opt for driving.
Edit: I should say, I mean in the summer. In the winter, you might want to watch out for things like winter tyres etc., which will add to the hassle.
Post edited at 21:45
