Fading out effect a led stripe which has just 2 wires

While working on a project car, I've run into some troubles. Wanting to add red led stripes to the car tail lights, I also want to create to fading effect, only issue there is the lack of a data cable present on the led stripe that I can use. My question is, how can I achieve this?
Link to the led stripe we purchased.

For a simple 12v LED strip you should be able to use an N channel MOSFET.

image

Note, the LED in the circuit represents the LED strip; the LEDs on the strip will have current limiting.

The voltage would be 12V.