Camry :: 2003 LE / Metallic Smell From AC?

I'm cleaning my mother's 91K mile 2003 Camry LE while she is out of town. The interior has a horrible and somewhat strong metallic smell that after some work I've eliminated the smell from the interior fabrics but it comes back after a while when you are driving with the AC on. It's 100 degrees here now so it's on high all the time. Then when I park the over night, no smell anymore until you use the car again and it doesn't come back immediately. I did a evap core clean with Klima-cleaner foam and used a febrese like product on the headliner, seats, carpets. I'm also using a clip on fan and some odor absorbing products while the car sits in the garage. The cabin filter has been out of the car during these processes but a new is installed now.

What can be done about this smell?

Other then that smell: The interior is in great shape and needs very little cleaning. Typical for a retired person's car.

The paint is the worst part of this car, dull and slightly oxidized but my test on the hood with my Flex Polisher and HD Uno (after washing with dawn and claying) means I won't have to make too many passes with the buffer to get it ready for a couple of coats of Duragloss sealant.

The engine looked pretty dirty but cleaned up easily to almost new looking. I changed the spark plugs, air filter and put on some Bosch ICON wipers. I'm not even sure if mom drives in the rain anymore.

The tires are 7.5 years old and dry rotting so bad you can barely read the brand and model, they are Michelin but I'm not sure which one. I'll get a new set of Michelin Premier AS's put on next Saturday.

I did order some new speaker grills for the rear deck. I had to scrape the black stuff off the inside of the edges of the glass and I conditioned all the seals with Wurth Rubber Care but I'm pretty sure that living in Texas the black on the glass is just part of Toyota life??? I don't own a Toyota myself and none of my 4 cars have this kind of issue (or the AC smell).