No you're not stupid for thinking that way. Actually, you're just being considerate and I'm hoping you're planning marriage and family down the line. If you get the Z, don't be dumb and use protection until you are ready for kiddies.
I'm in a long relationship with my girl and I still get the Z. I already discuss it with her the disadvantages and she says get whatever makes you happy since there's already another car for any "family" things. Plus, mines likes the feel of being driven by a boy in sports car.
Z as a daily driver...let's say while it's exciting to drive, it sucks for cargo space. My '92 240sx has backseats and lots of room at the trunk.
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