We have a Chausson 2017 718XLB noticed it leaked water in (dripped ) and also found at 50mph + it had a wind whistle, Dealer said this was common, maybe others have this problem on same make or different make as same parts are used on various makes. Having it replaced under Water ingress Warranty, so I suddenly realised for us it pays to keep up the Habitation Servicing which in Chausson's case you have to have it done by the Chausson Dealers