We have a nearly 1 and a nearly 3 year arriving on Monday for 4 nights and are desperately trying to find a cot and car seat to either (preferably) borrow, or buy before then. We live near Guingamp so ideally not more than an hour away ......
....in the Cotes d'Armor, Brittany
I am an hour and 12 minutes away from you (st Cast le guildo) and I have a portable cot that you are welcome to borrow.. no car seat unfortunately.
It might be worth your while seeing if their are any vide greniers around your area this weekend. some specialize in things for children.
You can get lits-parapluie (folding/travel cots) from most big supermarkets for about 50€. Car seats are more expensive but not worth buying second-hand, you don't know if they are reliable - can't the parents bring the children's car-seats with them? If you are going to have them visit more than about twice in the next couple of years it is worth getting the lit-parapluie, they fold away to nothing.
Thanks everyone but a french friend has come to the rescue and both the cot and the car seat are arriving on Saturday (fingers crossedQ!)