I have an '87 240 wagon, looks great, great mechanical shape, never been hit, etc.

The problem is the driver's side floor is rusted. Mechanic says under seat and up to rocker panel and across center a bit, but does not think the rocker panels themselves are rusty.

My question is this: I don't live in an area where rust is a problem (GA). Should I replace the floorpan or replace the car?

My main concern is that this is the car where my four children ride. Their safety in an impact is my primary concern. If there are repair welds in the floorpan, will this effect its crashworthiness?

What to do????

Thanks!