I searched, found lots, but I still need some advice. The thing I wish existed is similar to the psi3 ecu monitor http://www.psi3.co.uk/products.html I don't care about modding my ECU; my wagon is stock (for now). But the psi3 clock-pod mount is the type of thing I'm thinking. The features that exist in my dream add-on are:
  • turbo timer
  • boost gauge
  • shift light control (maybe even a light)
  • "cruise speed exceeded" beep with 60 s cycle
  • battery voltage low warning
  • clock
  • count-down tripometer (miles to go)
This is basically a combination of some features in the psi3 pod, a turbo timer, and a BMW's trip computer.

First, does something like this already exist? Second, what's the easiest and/or cheapest way to make one? Thanks