I have a 1997 e350 club wagon xlt and the passenger side lower dash panel is not properly secured. Behind it I found a metal box which is pretty rusty.

Can anyone tell me what it is and if I cpuld be worry about the rust? Should i try and clean it?

Any advice would be appreciated.

 

It's just a mounting support for whatever resides above it. No, I wouldn't worry about the surface rust on that plate. Any piece of bare steel in your van will have some rust after 26 years from humidity.