So we shall be taking this
[ Register or Signin to view external links. ]

And turning it in to this
[ Register or Signin to view external links. ]

---

Step 1 Open it in Paint.NET (Using v3.0)

---

Step 2 Duplicate the background layer (Layers -> Duplicate) and then apply the Sepia adjustment to this new layer (Adjustments -> Sepia)

---

Step 3 Apply a blur to this layer (Effects -> Blurs -> Gaussian Blur). I would recommend between a 2 - 6 pixel radius.

---

Step 4 Switch to the Gradient tool, and make sure it is set to: Linear gradient, Transparency Mode, and Normal Blending. These options are in the toolbar right below the buttons for quick actions like New, Open, Save, and Print.

Next, draw a gradient from the rear window of the car to somewhere closer to the front of the car.

Well that looks cool. To get a better feel for what you have done, you can turn off the bottom layer to see what the top layer looks like:


As you can see, this tutorial's effect works by removing portions of the top layer in order to let the bottom layer show.
You should re-enable the checkbox/visibility for the bottom layer at this point, if you haven't done so already.

---

Step 5 Now we want to oversaturate the original part of the image. To do this, click on the bottom layer and then duplicate it. Next, set this layer's properties to: Glow blend mode and set it to whatever opacity gives you your desired effect.