RUST!
 

hey guys, i started to get surface rust on my wheel wells so about 6 months ago i sanded the paint off all the way to the rust and wire wheel brushed that off to so there was no more remaining, then i applied roll on bed liner ( i did a very good job and took my time on all of this), but i just went to the carwash and i looked and the rust is coming through the bedliner!!! any ideas on what to do?? i wanna fix this before it eats all the way through the metal. any help/what have you guys done? or did i do something wrong?