I feel like this article is for people who only own DVDs and have never been on long road trips (like 16 hour + straight drives). So I would have to buy DVDs of any movie I might want to watch, in addition to the Blu-Ray copies I already have..

Except by adding a monitor to it (intended for viewing from the back) IS a method for defeating nanny-state protections. What you are doing is no different in concept (using in a way other than the manufacturer intended) than jumpering wires.

It is actually just a lead going to a ground or +12v (depending on car) wire in the gearshift that tells the unit it’s in park. Only one model is made of each.