Maybe hooking it up to the headlight socket with a kill switch might be better so when your not using it it can be shut off rather than having it on at night and you have no use for it and save your battery!
could you explain (better with photo) where do you take 12 V exactly? I took out headlight socket, opened it but did not figure out how exactly connect to it, least invasive way. Wires going to the socket are really short.
Another way is to wire it to the battery, its easy to connect, but a lot of disadvantages:
- wiring will be more complex
- need a fuse
- risk to drain the battery by leaving something plugged when engine is not running.