This is not intended to be a jerk comment.
I'd get a different car to transport a bike. Its just not the kind of vehicle you want to transport something like that unless you had a trailer hitch which(not being mean) again, is ridiculous on a Z or any sport coupe IMO. Not to mention the possible scratches and various other forms of damage to the vehicle.
To each his(or her) own, but I wouldn't attempt this.
Here's an alternative option: Buy a fully collapsible bike for the trunk area. IDK just a thought.
A Really Good Collapsible Bike
BusinessWeek
Good luck with your search!
