How can I get some wires from inside the car to the engine bay? I have just bought a boost gauge for my Vectra C Turbo. It's a stack gauge but this time it's electrical. It comes with a map sensor and I need to fit that to my firewall on the car dunno.. . I take it thats just near to the back part of the engine bay? The map sensor needs to be facing down over for some reason also. Next up is getting the vac line into the map sensor thing I got. Any help would be great