,99 r/ bumper installation ??=

i just bought a 1999 escort sedan. the rear bumper has been replaced. on the drivers side it ain,t staying secured properly. the little forward snap thing ain,t holding the bumper up against the under side of the fender. also = on that under side of the fender where the bumper meets the fender there is alot of rust showing. should i use a nut and bolt and washer to hold it up . and then run a line of black silicon along that gap ??

That's how I'd do it. The rust is probably keeping the clip from holding the edge of the bumper cover on. If there is enough of it there you could drill a hole and countersink a tapered phillips sheetmetal screw and touch it up with paint.