Getting a power cable into the boot - how?
 

I'm trying to run a fairly small power cable from the battery through to the boot, preferably via the passenger side of the car. For the life of me I cant find anywhere to go through the firewall. Am I missing something obvious?

Thanks in advance

Yep, I managed to run a massive power cable from the battery to the boot in my car without issue.

Have a look at the bulkhead inside the engine bay on the passenger side, you'll see a lovely big wiring sealing grommet where all the engine bay wire goes through towards the ECU and fuse box area by the passengers feet. You can run the wire along the existing loom and cable tie it to the loom then either pull the wire through the existing grommet or push a tiny hole on the underside of the grommet for the wire to go through. If you do it that way just ensure the wire angles upwards slightly as it goes into the grommet so any water drips away from the grommet and not down through the grommet into the footwell.

You'll need to pull the carpet forward and get onto your back to look up behind the glove box but you will eventually see the wire coming through. Once inside the car you can pull all the plastic trim sections off the inside of the door foot step and run the wire along there with the existing wiring loom. Don't be scared to do this they all come off and go back together just fine. You may have to unbolt the seatbelt from what I remember to get them off and through. Once they pop out of the rear door step trim you can go straight under the rear seat (which is only 2 bolts to remove) and into the boot area under the carpet.

Simples!

Alternatively you can run the cable across the bulkhead and there is a grommet up above the turbo which you can use. Access is easier from inside the car as you only need to remove the lower trim and then you can see the cable enter by the steering column/clutch peddle.

Thanks for the advice. I went through drivers side in the end as that's where my defi cables go through. Probably for the best to keep power away from the RCA cables.