unique icons per category?
 

Is there any existing mod or programmers who can make a hack/mod that will allow me to change the forum home status icons to unique icons per category?

For example

CARS
PLANES
BOATS

each would have thier own old/new gif icons for the forum home?

Check this mod. When setting the options you can specify if the icon goes next to the status icon or replaces it.

This is not my mod but be sure to read the last few pages of posts to see my fixes for sub forum icons

https://vborg.vbsupport.ru/showthread.php?t=244351

You can do that directly in the forummanager as well, by editing Prefix for Forum Status Images.
step1: create a custom folder in the statusicon folder for example cars.
step2: create custom icons and name them cars_forum_new-48, cars_forum_old-48, etc
step3: edit the forum and in Prefix for Forum Status Images add cars/cars_

Then it will show the custom icons on forumhome.