When we were out shopping for a minivan we chose the 06 MPV GT based on the reliability we'd heard about after some prety extensive research. After 6 years of production we figured all the bugs have been worked out.

Rust wise, we have first gen RWD/4WD MPVs running around rust free here in the GTA, and when our MPV was in for a regular service call we were shuttled in a 2003 MPV with 200,000 kms on it that was rust and rattle free. Given the way these dealer's mule-vehicles get treated, that pretty much resold me. The model year of yours (2004), it likely could be another paint failure situation as noted in the article for 3's of this era.
That all said, I'm still RustCheck-ing it annually since it's The Family Transport.

Better safe than sorry!
The 5GT we have has been great, given the underpinings of the platform are 3. We have five people that are various make 3 owners in my company including a MazdaSpeed if I recall. They thought I was nuts at looking at a Sentra SE-R over a 3.