I understand exactly why the function of automatically returning ambulances wasn't implemented by default. My buddy and I have used, loved and appreciated this mod in our own two-player environment for maybe a little over a year now and one of the private edits I've made is adding and editing a couple scripts, one of which has allowed ambulances to return on their own based on my personal preference. If it's alright with Blackout I have no problem giving you a copy of that script for a simple copy/paste fix to your dilemma, but only upon Blackout's approval.