You need to:
1.) Purchase a cheapo car tv tuner from ebay (the ~$100 models that have seperate inputs);
2.) Due your own due diligence and go on the g35 forums on the net (not sure which website but I know there is one big G35 forum somewhere on the net - you may want to google it);
3.) Find/purchase a cable that will allow you to utilize your G35 screen - the audio/video forums of the G35 websites should have tons of more information.
Also, have you perhaps tried google?