Bmw e30 Service indicator shift light

[XLR8]

hello M42 members ,

i'm wanting to install a shift light indicator for my 318is ,
ive seen some ppl how build and sell these si lights ,
ive tryed to contact some no response can someone here help me with this mod ?

here are some links of the mods

https://www.youtube.com/watch?v=Y4mTS7gC0ns

here wideband display

https://www.youtube.com/watch?v=__tOskk0aus