I am trying to install an amp. I have just spent the last 40mins trying to get the power from the battery in the engine bay into the car so i can run it to the boot. I have failed.

Can anyone please help me with getting the power through the firewall before I go mad and have to take the car out for stress relief.

Thanks in advance

 

I have now dont it thanks to the chiark ice FAQ. A very helpfull web page. Now just need to find somwhere to mount the amp