Hi erm even i have Fm Kit installed the best way to use it is to turn on Fm Kit when you get into the car now if u make or recieve any call it will come straight through your car radio of obviously tuned to correct frequency! but unfortunately if your Fm Kit is not turned on and phone call comes in then you try to turn it on it just doesnt work maybe thats how the program is made. I know its annoying as when i am driving and that happens i just have to reject call and then turn on Fm Kit and call the person back! Maybe someone could change that bit of the Fm Kit exactly like you said so it would auto connect but thats where the problem is! how would n900 know its in the car and it should auto connect to Fm transmitter? As if you are not in car and n900 auto connects to Fm Kit you cant hear any thing through the n900 speaker! So thats what the problem and reason is hope you understand and it helps.