relaying brake lights to a switch

It's quite tight under there but you need to remove the plug on to the switch. It has a spring plastic piece on the side which you press in to release and wiggle/pull the plug off. It gives you a little bit more to get access.
You now need to identify the "live" wire. It should be live even with the ign. off. Then it's simply a case of cutting it and extending the wiring through an on/off switch.
I added cruise control to mine and had to wire a cut off to the brake switch.
Just to add I don't suppose it really matters whether you cut the live wire or the earth wire.
Either way you will interrupt the circuit.

I quite fancy doing the opposite

.... wiring the brake lights to a switch so that they'll come on when I press the switch
........... is that possible ??? :huh:

I could then have some perverse fun with taxi drivers and bairns occasionally tailgating me :evil:

Halford wrote: I quite fancy doing the opposite

.... wiring the brake lights to a switch so that they'll come on when I press the switch
........... is that possible ??? :huh:

I could then have some perverse fun with taxi drivers and bairns occasionally tailgating me :evil:

much better would be a KC daylighter with a 150w bulb mounted on the rear door aimed at their eyes :evil:

Halford wrote: wiring the brake lights to a switch so that they'll come on when I press the switch

Why bother? just tap the brake lightly, it's enough. The method Darthloachie suggests below is even better, nothing like seeing two "headlights" facing you in your lane

Get an old blanket slam it hanging out of the boot door so it hangs over the light

Or use some sort of tape