I bought the BRZ after my daughter turned 6 months old. Rear facing seat was fine although my wife (5'2) complained about how little room she gets in the front passenger seat. Do note that the front passenger area goes deep down the glove compartment. I am 6'2 so no one could sit behind me
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My daughter is now 19 months old and she likes the BRZ a lot. I have the Recaro child seat in the back. The seat freed up quite a bit of room once you turn rear-facing into front facing...
Overall I did not regret my decision to sell the Saabaru (WRX wagon) to get the BRZ. We also have a big SUV as the family hauler.
Hope this helps.