I've had 3 Winnebagos, 2000, 2002, 2004 each 7 yrs old when I purchased, and I kept each one for 2 years. Never had a leak/rust issue around the windshield with any of them, nor any evidence of prior leaks/repairs. I'm don't doubt that some coaches have rust/leak problems but I was fortunate.
Kent & Sue & Belle
2019 Allegro Bus 45OPP Lovin' it