Thinking of getting a Z

[DJEMPowerM3]

Hello,

I am thinking of making the switch from M3 ownership to
a 370. I love my bimmer it is a 2004 Carbon Black SMG
with 57000 miles. It is a blast to drive but I have always
admired Z cars and the new body style is pretty sexy.

What are the some of the costs of owning a Z?
Would the 370 make a good daily driver?
What are the costs of maintaining?
Is there room in the back for a large suitcase?

Thanks in advance.