Thanks. I spent a lot of time playtesting and also bothered my fiancee from time to time :) It's great to ask for feedback early if you have that opportunity.
I was sometimes getting lost myself, especially after adding 3rd ambulance, but I had so much on my mind that I didn't register it as a real problem. In the hindsight I can see trivial solution that would probably solve the problem... Just add corresponding number in front of name above ambulance.... It would take 1 minute, but oh well :)