Wife's 2013 Equinox is rusting along the bottoms of the front doors where the outer panel is crimped on. Again. Was fixed back in 2015 when it was still within GM's 3/36000 rust warranty. Noticed the other day that the rust is showing again. Now it's out of the rust warranty unless it happens to rust all the way through in the next year. Google turns up that lots of Equinox/Terrain have rusty doors and GM is mostly "too bad, so sad" about it. So, short of hitting it with rust converter, primer and touch up paint, what can we do?