Thats not an uncommon deal with Winnies - and it seems to still be an issue today;
2015 Winnebago Vista Equipment Adaptive Service Bulletin 381914
Action Number: 10057526
Service Bulletin Number: 381914 Report Date: May 11, 2015
Component: Equipment Adaptive
Summary: Winnebago: see document search button for owner letter. To prevent and/or protect the champagne sidewalls from failed sealants or cracks, eternabond tape seal is applied over roof sidewall joint. Model 2015 vista, itasca, sunstar.
And sure enough, right from Winnies own web site;
How To Seal Your RoofYou'd think after how many years and how many failures they would have come up with
something better by now. Apparently they don't see this as a problem. Oh wait...yes they do, see the TSB above.
When it comes to buying a new MH we all have choices - I know one I wouldn't choose.
