Stand alone alarms are easy with the 370z. Just apply power to them and add the siren and all the sensors you want, you might be able to do a engine kill as well. The only thing is with ones that you try to integrate with the Z that gets messy and frankly not anyone that I know has done one. I do know there is a wiring harness for it but as far as remote start and all I doubt it.
Click the link in the 3rd post. But you will have to sign up.
09 nissan 370z alarm wiring needed