passing model data to a plugin called within that model

I am making a plugin which extends ActiveRecord::Base

I have the plugin working in my models in other aspects. I would like
to pass in some data to the plugin, but I can't get the data I would
like.

so if I have:

class Stuff < ActiveRecord::Base
    belongs_to :thing

   my_plugin :id => self.thing.other_id

end

it chokes on figuring out what to do with self.thing.other_id.

I checked, and self isn't recognized at the point that I am calling
my_plugin

so if i do :

class Stuff < ActiveRecord::Base
    belongs_to :thing

   my_plugin :id => self.class.to_s

end

when I print out :id the class result comes back as blank.

Is there a way to do this?
The closest I can get is I can sort of do self.send(:thing).send
(:other_id)
It didn't 100% work, but it was starting to get clunky, and I didn't
pursue the error I was creating.
There has to be something obvious I am missing.

thanks,
Charles