That's not entirely true. Boarding Planks do:
I'll see about updating GCE to be clearer about this as it's a good point. Once I can get our server to understand that no, its hard disk is not full (it's 93% free!).
Good point on the boarding plank, i think for clarity, you could remove the reference under the boarding plank, or, actually, now that I've written what I have below, you can likely keep it as an example.
Core Rule Book:
Vehicles usually have the option of Gubbinz. If you’ve not spent much time in Britain you might not have come across this rather odd word. It’s a vague term for “gadget” or “gizmo” and that’s what Gubbinz are in GCE. Adding Gubbinz will provide upgrades and options to Vehicles to improve them in some way. (See your faction for specific gubbinz)
When a Vehicle has Gubbinz of some sort, they’re added to their Hit Location Tables and can be damaged during a game. Unless otherwise stated, they’ll be fixed automatically by the time the next game happens.
Some Gubbinz have to be mounted in a specific quadrant. These are the same as the regular vehicle quadrants. The quadrants are not slots. Mounting one Gubbin within a quadrant does not prevent other Gubbinz from being mounted in the same quadrant. Any Gubbinz mounted within a specific quadrant can only affect that quadrant.
For example, a Wrecker Ball mounted on the right side cannot swing over and hit opponents on the left side of the vehicle.
The specific Gubbinz available are listed in the faction packs. You’ll also find any number of other Gubbinz floating around the Internet that you may want to use during a campaign.
Gorker Morker Faction Book:
Below are the list of Gubbinz available to Gorkers and Morkers. Some gubbinz are required to be mounted in quadrants on your vehicle, see the GCE Core Rules under the Gubbinz section to see how mounting vehicle gubbinz into quadrants work.
For other faction books:
I dunno, I don't deal with them non-greenskin trash.
Just my suggestion, I'm sure whatever you do will be great.