I've seen a few pictures of boost gauges fitted in the A pillar in a variety of cars, is there a recommended one for a S4 and are they easy to fit or require any specialist knowledge? A web site (Edworthys.co.uk) do a nice looking "carbon" housing and have a Blitz MD Gauge (part 19475) gauge which looks OK. However, I've no idea on how to install. Any help or advice would be appreciated. Another, and probably stoopid question is, with 2 turbo's does the S4 require 2 gauges?