Perhaps it's some of these jobbies?
Can't find a better picture without the company logo on top. It's basically 4 holes allowing male pins to be fitted. Much larger than header pins on fan connectors but much narrower than a molex pin.
They seem to be pretty universal for LED strips to allow daisy chaining of several LED strips. You can buy male to male connetors and solder some wires from a molex to them or chop the end off and solder the wires to a molex or something.
These LED strips are for auto use so will have different plugs to what we use in PCs.
I assume they have 4 pins for RGB LED usage. Common Anode, R, G, B Cathodes. For a 12v single colour strip you'd only be using two of the pins.