believe it or not, the current limitations for the acc. wire on some decks is as low as 120mA (it's ussualy between 150-350 though). and to make things worst, most of the time there not fused. i know of a few unfortunate people who made this mistake already (of course they were trying to run a lot more than a couple leds), they didn't expect the limitaions to be that low.
I read the quick how-to he wrote, so im assuming he know alot about electronics, this is just a reminder.
the least you should do is double check the current limitaions.