Hard Wiring DashCam

I am trying to hardware three dashcams all on Prius's.

As of right now, I am leaning towards this guide:

From the guide above, the person only the following parts:

• Small ACS Add A Circuit Piggy Back Pluggable Standard Blade Tap Fuse Holder | eBay
• 12V 24V Female Car Cigar Cigarette Lighter Socket Plug Adapter Connector Hot New | eBay

Is this really it? I ask because I want to be cautious and not have to deal with damaging, or potentially causing fire hazors and what not.

I also know their are kits (Power Magic Pro) that do this job just fine and cleanly, but unfortunately, it costs north of $35 for kit, and with the intention of doing this on three Prius's, I'd really prefer to keep my cost low.

Can anyone confirm if this type of "hardwire" method would work, and is safe for the Prius? Or am I missing something here? I am also open to other cheap alternative ways to wire my dash cam, as both cig. socket ports are often used in both cars.