Depends on your purpose and priorities... budget, daily driver or track, number of seats, creature comforts, etc.?
NISMO 370Z is heavily overpriced for daily driving. If you like it for looks, get the body kit and exhaust upgrades. It should net you over 18whp anyhow.
335i is a very nice car, and you can't beat BMW drivability. It definitely had upgrade potential to overpower it's curb weight and outrun the 370Z. I wouldn't consider it much of a track car... you may want to consider a used M3.
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