I need to run a power cable from my engine bay to the boot. Where is the best place to run this through?? Pics would be great!!
51 plate S3
The easiest place is top right of the engine bay, under the wiper splash guard, near the pollen filter. There is an unused rubber grommet there which drops down behind the glovebox. Use a drill or sharp screwdriver to put a hole in it, then use a wire coathanger to route it through. Removing the glovebox makes it alot easier. On the engine side you can use the existing plastic trunking to route it down to the battery. There is usually a spare ring terminal on the battery which just needs an access hole cut into the plastic shrouding.
Inside the car: remove the screw holding the side trim in the passenger footwell and then prise up the doorsill trim which is held with metal spring clips.
You'll be able to tuck it under the remaining trim or you can remove the rear speaker panel and hide the amp behind it.