You can easily make cosmetic warp nacelles with some of the extras, then just make your actual engines "invisible" by shrinking them and turning them to face "inside" the ship.
I actually have a game going as a civilization inspired by Trek's Federation. Most of my ships are just "in the style of" the series, but this one was loosely inspired by the Miranda-class. With more effort I could have probably gotten something that looked like the real deal.
Here it is:
Again, it's not really intended to be all that accurate, but goes to show.
