track car upgrades

racer_X

I have recently started tracking my 370z. I enjoy the 370z and have learned a lot and I get faster every session. I have thought about some upgrades like a square wheel setup, an LSD, and maybe some coil overs. But my wife and I are started thinking about having kids. I'm afraid a 2 seater might not work for hauling kids around. And I would hate to sell the car shortly after spend the money on upgrading it.

I was thinking I have 3 options:
Keep the Z for track days and daily drive something inexpensive like a focus.
pro: I get to drive a familiar car on track
con: Seeing the Z everyday and not driving it that often would be frustrating

Sell the Z and get a 4 door 335i
pro: Nice car to drive everyday
con: 335i is a little heavier but many have successfully run them on the track.

Sell the Z get something fun like a WRX for daily driving and get an inexpensive miata or BMW e36 or something similar for track days.
pro: Something fun for daily driving
con: the track car will need some initial work and might be unreliable being an older car.