Hi,
I have a website Drupal 5 where an user can:
1) Create a node of type "Vehicle" (created with CCK)
2) Create a node of type "Track" (also created with CCK)
3) When the user creates a track he can link a vehicle to it, but the vehicle has to be his own, he cannot link just any vehicle.
Understanding how to do the third thing should be easy for someone more expert. To link the vehicle I have thought I can use the Reference Node field in the track node, but this will show just every vehicle, not only those by the same author who created the vehicle and who's creating the track. So I searched a module which could selectively hide certain voices, but I couldn't find any module doing just that.
I am ok editing PHP code, also if that means modifying/rewriting part of a module, but I can't write from scratch because I am quite new to Drupal.
I accept every kind of answer, even RTFM (which I have actually done, but I could have missed something, so please be specific in this case :) ).
Thank you.

Comments
Use 'Advanced - Views' mode
At the bottom of the noderef field config page, you have an option to define referenceable bodes using a 'views.module' view (only nodes that are retrieved by the view are valid).
Then it becomes a matter of adding the right filters to the view.