We've had two National RVs and have had to replace the windshields in both. Our first was a 34-ft Sea View. I had a discussion with the windshield manufacturer in Oregon, and was told that windshield stress cracks was a critical problem with National motor homes up until the year 2002. He said his records showed they had replaced a windshield in one 2000 Tradewinds seven times. He also told me that windshield replacements decreased dramatically after 2002. It seems that this was a manufacturing defect.
I also had to replace a windshield in our 2001 Tradewinds and was told by the glass manufacturer that they would not warranty the new windshield against stress cracks. Consequently, I bought add-on glass coverage through my insurance with $100 deductible that would not affect our rate due to a glass claim. I think the cost is about $95 annually.
I hope this helps in understanding the problem.
Aside from that problem, we loved both our National RVs and feel their quality is outstanding.
Larry & Norma, Dallas, Texas
2001 39 ft. National Tradewinds LTC
2003 Suzuki GV ] PressurePro TPMS