To be honest, IMHO, the slight positional problem with the text is nothing compared to other technical problems. For example, do you really want the horizontal scan lines in the image (ie, as an intentional grunge effect), or would you prefer to have them gone?
Also, how did you get this image? Is this a scan of some printed art work?
If it's a scan, have you thought about simply starting over, basing your final design on a much higher quality image like this:
http://images.newcars.com/images/ca...4dr-Rear-wheel-Drive-Sedan-Exterior-Trunk.png
...changing the color of the car, darkening the scene, adding the lettering, compositing in the man (fireman?), etc. It's not as hard as you may think, and the final result will be of vastly higher technical quality.
Tom M