the mazda3 used to be terrible for rusting but they changed something in 2007, a collegue mazda3 was from 2006 and it rusted so much thast it had almost no resale value, my gf mazda3 from 2008 sill looks new...
p.s. I live in a place were salt used to be applied aggressively in the winter. Nowadays they use more sand and only use salt when the road conditions really requires it. but it's a recent development (3 years at best)
