how small can those vinyl graphics guys print? maybe you can have them print out small words on white or grey vinyl with a factory looking font, and then transfer them right to your buttons?
Actually, it'd likely be better to use the vinyl graphics guys to make a screen and then use the screen to paint the part. Otherwise, tiny vinyl parts = not much adhesive space ---> tiny letters all over the car.
that was what a laser etcher told me would have to be done to get the oem back lit looking buttons. we ultimately decided on a slightly different process but that should work as long as you can get the paint to stick.
here are some other options (this is from an email with my engraver):
Options for the back-lit buttons...
Clear Acrylic engraved with the text, or not engraved where the text should be. Best done when the buttons are cut out. (for perfect alignment)
Opaque Acrylic with the letters cut out of clear, or another color - slide in the letters and glue them in place... Cool effect... (More $ though, as multiple pieces of acrylic are cut out, and multiple colors)
Transparent Acrylic in colors, such as a Green or red, with Engraved letters on the - or engraved reversed on the back, so you can see them on the front.
Two pieces of Acrylic, front piece is clear, back piece is opaque, except where the letters are removed.
Three pieces, with the middle being a sandwich providing the letters, leaving the back flat to make mounting to the switch easier. (Although, depending on how you do it that might be a moot point.)
New System in progress:
Phaze TD1500 ~> Dynaudio MD130
Phaze TD1500 ~> Seas g18rnx/p
Zapco Ref 500.1 ~ 12" tc-9
Behringer DCX2496 ~ Envision Electronics psu