Single DIN In Dash

DIN is nothing other then a measurement
(well, thats not completely true, it stands for German Institute for Standardization, but when we talk about a singe DIN or a double DIN radio, we are talking about the dimensions)

so, you need a cage, like this



then you seen which one of the little shark fins makes a good tight squeeze with the panel, and you fold them in

like others mentioned, the radio just slides in and locks into that cage