In reality there would be tough to avoid spider cracks from tower mount… Current Horizon Mold was around 2004 (before tower era) and there is no provision for extra meet in the area tower would mount… There are tremendous force will applied to tower mount just going through chop. I would recommend to ask dealer to champher/counter sink holes and change gasket to other material than Factory one. (stronger rubber since factory one would stretch thin and mount will dig into gel) My Arch is a Factory OEM but installed by dealer who is as anal as myself and try to avoid this issue. So far so good but this might be a matter of time....
I do not believe this is an only for Four Winns but other manufacture as well. We have a family friend who has 2009 Cobalt 242 with tower and already develop rather large crack from the mounting point......

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