The simplest way to model is just make cylinders the correct diameter and drop them in as space holders. You could make a couple of configurations to similate different ride heights.
If you want to model the spring; it can be done with a simple helical sweep.
If you are asking if you can make your actual model of the spring real time compressable, I would have to say no; unless 2005 allows this but I havent installed that version yet.
I dont quite understand EXACTLY what you have asked for but hope this helps. Be direct and specific with your questions.