Get as much work done as you can on the X now that its stationary - once that trans is dumped back in you won't want to work on it you'll want to drive
Does she have a coupe with Harmon Kardon? If so, I think that the tweeter/midrange "pod" takes those 2" Vifa Woofers that we found for the rear E53 door midranges as well, and then just pair it in the pod with the tweeter of your choice - there is a thread on the E46 boards about it -