Enterprise or similar

I really wouldn't want to try and put an Ent on the roof of a car. You'd need some serious lifting effort for a start, at least a 4 person job and perhaps more than that. And that's assuming, as others have said, that the car and roofrack will take the load. I'd echo the Laser Fun point. Nice simple fairly light  hull, simple rig, some had reefing points for the main and furling jibs. Indestructible tubs too, which I guess is what you want in something you'll presumably leave for quite a while.  The main thing to check is that the mast splits - I once owned a Laser Fun and the mast split into two parts, a bit fiddly but I doubt a 1 piece mast would fit onto any car without a severe overhang. Not expensive boats either so you might find one for £500 at a pinch.

Edited by Late starter - 15 Nov 10 at 7:12pm

I just bought an GRP ent for £180 for the uni sailing club. Although it will almost certainly be overwieght it is watertight and missing only a rudder and jib.  If you were set on an ent looked around a bit you could get an ent for <£500 and use the change to pay for the more expensive ferry, loaning a trailer for the journey.

420 is same or heavier than an ent, and very hard to get more than two of you in.

A boat like a Laser 2 or Fun would roofrack very easily, whereas an Enterprise is pretty wide (wider than the car) and deep. There really are very few car topable doublehanders once you are bigger than the Firefly/Graduate/ Comet Duo sort of size boat. Mind you, in frace there are rather more - do you know anyone out there who could look at any for you before you go? Does Ebay in France have as many boats as the UK one? 

A Europe is a small singlehander, easily roofrackable, but not the same sort of boat at all to the Enterprise.