Is it possible to paint the panniers? i want to paint them black as they look scuffed and slight marks everywhere.

I believe you have to use a certain primer for plastic but im not sure, anyone done it or know of a guide anywhere?

thanks

I've been reflecting on that too. You're riding an RT, so are your panniers already painted body color? If so, standard painting techniques will apply. If they are still black plastic, you'll need a primer formulated for plastics first, or the paint will peel up soon enough.
The real trick is to clean the plastic parts very very well with a wax and grease remover for body shop use. The trick is to wipe the panel with a rag soaked in the W&G remover, and then wipe it dry with a clean cloth. The W&G remover lifts the junk to the top of the surface, but if you don't use a clean dry cloth to take that off, it will settle back down onto the panel as the product dries.

Krylon Fusion Paint. Clean with ammonia based cleaner (window cleaner?) Fuses with the plastic. Primer will prevent it from fusing with the plastic. Will be trying it on mine soon, have seen decent results on car plastic parts. Will let you know how it goes.