[Tomko]

Before GM pioneered the use of double-sided galvanized steel in its vehicles MY1991, there was the Ford Duraguard System in MY1977. It included anti-chip treatments at the rockers like you're describing above.

 

[Tomko]

Ford brought the Duraguard System to market because they were pretty much forced to by the market and government.

Seeing cars driving around with massive rust holes was commonplace in the 1970s. I personally knew two people who owned Ford Torinos that had completely rusted through in two years. Ford was under intense pressure. And in 1977 the government of Canada took action requiring all manufactures to warrant their cars from rust perforation for three years.

The three things you can do today to keep your car from rusting in 10 years are:

1) Paint protection film on all leading edges. Sold by 3m, X-pel and others, it's not cheap. But it works. $$$$ one time.

2) Splash guards. Cheap, and if installed properly, it works. $$$ one time.

3) Wash your car once a week. Not inexpensive, but some car washes you can subscribe to for a monthly fee. $$ a month.

But most people will drop $30-40K for a new ride - but balk at the above because it's just too expensive. That's what academics call a false economy. Saving money so you can spend more a few years down the road.