V19 showing up on number stickers on cars, also lettering on number plates being cut off on some mods, cannot for the life of me figure out how to fix this as it's annoying...
Other than that I'm loving this sim...

There is no fix - it's how the mod creators have set it up. In the shown case it shows what you have set in your numberplate - it's meant to use a 1 or 2-digit number.

You can change the Numberplate in
Options -> Driver