Hear me out, but it might be complete twaddle (next step to foil trick)
Reading the foil trick, it seems that light can be reflected back through the LCD instead of being lost.
Now my suggestion is, if you take two thin sheets of perspex/acrylic, one needs to be evenly frosted/etched and the other doesn't, some foil, and white EL wire.
Take the frosted piece of acrylic, and using hot glue, build a network of EL wire, zigzagging back and foward across the sheet (like the back of a refrigorator, or car radiator (might need to experiment with the number of rows.
then take the second piece of acrylic, and using contact cement, or spraymount, stick the foil to the acrylic with the shiny side out.
Now once all the glue has dried, place the foil onto the EL wire side of the piece of frosted acrylic, and seal the whole thing with Duct tape round the edges, then mount that in place of the standard foil on the back of the TFT.
I'm hoping, because I don't have any kit to try it with yet, that the EL wire will illuminate through the TFT like a backlight, but because of the frosting/etching, it will be diffused fairly evenly instead of showing in lines, with the foil behind reflecting even light through and helping with the diffusion of light.
Now if you were to put a pot into the line into the EL wire, you could then control the brightness of screen (brighter in daylight, and darker at night).
Any thoughts on this from people who have had some TFT experience?
Re: Hear me out, but it might be complete twaddle (next step to foil trick)
One thing I'm thinking of is will it fit?
Well, if you used something like 2mm acrylic, you are probably looking at adding 6-10mm depth to the back of the screen, depending on what the diameter of EL is.
That might cause a problem in soething like a Xenarc or other cased screen, but if you are building your own enclosure, or dash mounting you just need to take it into consideration.
Another issue I thought of after posting, was that of contrast. If I pump up the brightness too far, I will need to ensure that I can get the contrast adjusted so that it doesn't totally wash/white out.
This MP3 player site does a great job of what I;'m planning, but without the thickness.
Whole site isn't too bad, worth a look arround.