I ordered some samples and tried it with LEDs.
The translucent t-molding doesn't diffuse light at all.
You can't see much light unless you're lined up with the slot looking straight at it.
Scuffing it up with sandpaper would help, but then you have scuffed up t-modling.
Might not be too bad if it's really fine sandpaper.
If the edges of your sides are dark(mdf color), it shows through and looks bad too.
I'd definitely paint the edges white or silver if trying this.
IMO, white t-molding and a well placed blacklight would probably look better.
Don't let me stop you from trying.
Just don't sink a bunch of money into stuff to do the entire cab until you've worked out the kinks on a smaller (cheaper) scale.
I'd like to see someone make it work.