What we found were Ford Focus Speakers for pre 2005 models, and it's 5x7 but 6x8 will work as well.
According to forums, it might be 5.25" or 6.5" as they seem to be mounted on a bigger 'backplate'. For inquiries, please contact Ford customer services on 1 (800) 392-3673.
Upgrading your car speakers is one of the easiest ways to get better sound out of your car stereo system. Speakers come in several sizes and price ranges so it is helpful to have a basic understanding of car speakers before you go shopping.
Here are some general tips to follow shared by Autos.com.