This is a new plugin I'm working on. It aims to expand the functionality of new vehicles, in a centralized manner, so, hopefully, you won't end up needing a different plugin/script for each function vehicle models authors want to implement in their models.
Currently, the vehicles are configured via XML files, alongside the changes needed in the model itself. So, no, it doesn't support already released models.

Current Gadgets

• Ladder

  This gadget will allow you to add a working ladder to your model, which can be controlled via the NumPad.
  

  
  XML Entry Example

• Outrrigers

  This one, adds animated outrrigers that can extend and retract by pressing a key.
  

  
  XML Entry Example

• Radar

  This one is similar to the already existing VEHICLE_WEAPON_RADAR from the vanilla game, except it doesn't take a
  vehicle weapon slot and you can modify the rotation speed.
  XML Entry Example

TODO

• Implement collisions, so, for example, you can climb up the ladder.
• Add more gadgets.

Firetruck shown in the videos: MTL Botlle Nose Ladder 15EX Truck by GlitchGamer

Any vehicle developer interested on implementing this plugin, with the current gadgets or with an idea for a new gadget, can contact me to discuss the implementation details, or if the gadget idea is possible.