Back in 2003 I was looking for a new compact car. I checked out the protege, VW Jetta, and the Nissan Sentra. I bought a new 2003 Nissan Sentra Se-R, mostly because of the bigger 2.5 engine. It was a little pocket rocket. Fun car. The Protege just didn't measure up. I was also concerned about Mazda's poor reputation at the time for premature rust. I'm still happy I bought the Se-r. I wouldn't buy the base Sentra with the 1.8 engine, even today. As for rust, it held up fairly well. It started life in Ottawa, Ontario, and found it's way to Newfoundland when my son bought it from me. Last I heard, it's still on the road down there.
As for early Mazda 3's, wow. The few that are left on the road around here are terrible. Major rust buckets.