Adding additional off-road/rally lighting

[cjm]

I want to add a pair of 100W off road lights on a separate switch from the headlights or fog lights.

So, expect I need a 20 or 30 amp fused circuit.

What is the best way to add that?

[spdracrm3]

you can purchase Piaa heavy duty relay/harness kit http://www.piaa.com/store/c/66-Wiring-Harness.aspx and use the little auxiliary fuse box next to the main fuse box to get power, just install appropriate fuse(connectors are available from bmw) and find a place to mount relay/switch .