What to do with my '02 PreRunner with rusted frame.

Thanks for the feedback. Interesting that you traded your truck in at a Ford dealership, even if they also owned the Toyota outfit next door. Hadn't thought about going that route, but will not deal with Toyota again. Dealer totally uninterested even though we have purchased and/or leased 6 or 7 cars from them over the years. Corporate conveniently lost our inquiry for 5 months, though they claimed the ticket was still open and someone would get back to us.......
We have the same ethical issues with the car going to someone unaware of the problems, so can't sell except as junk. Figured the thing was worth about 7K on a sale or trade before the rust news, and now looks like it's worth just about zip.

May take a drive to a different brand dealer though, and discuss a trade. Thanks for your input, and bearing with our bad experience retelling.