Start with a new file, white background, 16 million colors. Begin with something that's quite a bit bigger than the size you want when you're done. You're going to want room to maneuver your text. For the example I started with a file that was 400 x 400. Make your foreground color blue (RGB 0,0,255) and put in some text. Be sure that 'Floating' and 'Antialias' are both checked when you add the text. A font with reasonably straight edges seems to work best. Here I've used Times New Roman 48 pt. Be sure to leave your text selected.

Now go to Image: Rotate. Check the box for 90 degrees, and the box that says Right. When you're done, move the text close to the right hand border of your window and deselect it by hitting [Ctrl} D.

Next, go to Deformations:Wind. Check From the Right and make the strength 20. Your letters will blur and you should get long streaks.

Time to make things a bit more three dimensional. Make your foreground color white, then go to Image, Other: Hotwax coating. Apply the Hotwax twice.

Next we take this image and blur it. This will serve as the glow around our vans. Go to Image, Blur:Gaussian Blur. Set the Radius to 5.00. This blur is the reason that your background color should match your webpage. Transparent GIFs don't deal with blurs very well.

Next we make sure that the text is easier to read. Set your foreground color to RGB 48, 48, 101. This is a nice dark gray that compleiments the other colors well. Other colors might work even better, so experiment a little until you get something you like. Now add your text again. Place it where your letters originally were, or offset it a few pixels if you like. Remember - it's a 3D look you're going for.

Okay, now with the Selection tool, draw a rectangle whose upper edge lies directly along the base of the text you just layed down. You should have something like this:

Next, use Deformations:Perspective - Vertical. Set the % difference to 100. Deselect and you're done. To finish up, crop your work and save it as a GIF. Remember, to set white as your transparent color, first make it the background color, and then go to Colors: Set palette transparency. Let the program decrease your colors to 256, and then choose "Set the transparency value to the current background color" from the popup menu.

If you think the text looks too dull, there are a number of ways to brighten it up. Here I've used Color, Adjust: RGB with settings of Red 50, Green 0, Blue 100.

Two more quick tips. The effect works best if the words you choose have letters with vertical edges at the beginning and end.
Finally, to make the letter recede into the distance UP rather than down, make your first rotation 90 degrees Left rather than right, and change the vertical perspective setting to -100.