If you want to link the ZR4 with the 9500ix, then you have to cable it.
We do make wireless kits for the ZR4 but you can only get the alerts on a Cheetah product, either the little display unit that comes with the wireless fitting kit or a GPSmirror or C100 camera detector. We don't link wirelessly with the 9500ix, I'm afraid.
A M27 and a Cheetah Wireless Kit would serve you well since the wireless kit only takes minutes to switch. Hardest part would be moving heads but still not a problem.
If you change cars that regularly, I'm guessing you work in a car dealership.
Have a quiet word with the guys in your bodyshop and ask them for some 3M automotive tape - the stuff they use to put car trim and badges on with.
I seem to recall some folks have used that successfully in the past so it can work quite well for jammer heads.
When you want to remove them, you have to heat the tape up with a hair dryer and it leaves no trace.