What is considered too much rust?

My daughters Ford Focus has been in Minnesota for a year (we live in ma) and we finally got it moved back home. The engine is in good shape, interior is good and most of the body is good but the bottom panels along both sides are getting eaten by rust. I’ll take pictures tomorrow but at least 1/4 of both sides has been completely rotted. Is it worth trying to fix it? I’m consider just using a bunch of bondo and wire mesh and rustoleum rust converter spray paint, not really sure what else to do. Suggestions welcome.

 

Need pics, but if you are speaking of the rocker panels, that's bad.

Thats a significant structural area, and mesh / bondo would jut be lipstick on a pig.

 

So if most of the lower body panels are rusted out it’s probably not safe? Basically the bottom panel that runs under the doors from wheel to wheel.

 

The X member that holds the engine to the body likes to rot off on the Focus so check that while you’re under there

 

I’ve been looking around and it sounds like replacing rocker panels alone is a pretty hefty price. I’m starting to think it may be better to just look for something cheap that is in better shape than this. I’m not sure spending money on it at this point is worth it.

 

Here a picture. Most of the bottom panel on both sides is in this condition

 

What you can see is going to be much worse on the inside.......

 

Yeah, unfortunately I've come to the conclusion that this will never pass inspection without some major body repair. It's not worth it so I've convinced my daughter to start looking for something new. She really didn't want car payments and this was her first major purchase on her own so she's emotionally invested in it but there's just no getting around the rust.