Would anyone know where I could find some trip computer buttons as mine has seriously been worn out? Is there some paint marker pen which i could use to shade in the worn out areas?

Why not just grab a Niko or permenanent marker and colour it in?

I am in the same boat. Yoiur best bet is to look out for TTrip computers that dont work, ie cracked screen, by it cheap and replace the parts.

I couldn't find one though so I bought another one....