1. Put a tee piece in the vac line that your going to run the gauge from
2. I Put my gauge just under the ashtray behind the gearstick, probably not the best spot, but kept things tidy. Used a Metal gauge holder from autobarn.
3. As i don't smoke, and its not tolerated in my car, i used the plug for the ciggy lighter as a source for the earth and constant (battery) wires. I then tapped into the wire leading into the light that surrounds the ciggy lighter for the gauge light.
4. Now i drilled a hole at the top of the windscreen plenum, then in the firewall for my vac line. Sealed it up good. then she was done.
Cheers
