Sounds like you've decided on extra car seats instead of an extra car.
Still, the 5 would fit your needs perfectly, IMO, because you already said you use the RX for long trips, which I perhaps mistakenly took to mean you don't need a bigger 'mini'van for long trip capabilities. We have a 5 and a Baja (not a WRX, but similarly fast) and despite LOVING the Baja I occasionally feel like taking the 5 to work. We have 2 kids under 6, but the wife often has another kid or even 2 more with her during the day.
On long trips (we have taken the 5 to southern AZ and back a couple times) the thing that gets to me about the 5 is not the space it's the sportiness. Sportiness is fun and nice but not for a 12-hour freeway trip. For that a big Buick is the best thing in the world because it's smooth and quiet. In any event, we've thought very hard about a trailer hitch to hold a cargo carrier w/sack or box in it for long trips. IMO they're better than roof racks for loading/unloading and for mpg. We'll probably get one if we start back up on long trips again.
Still, the 5 would fit your needs perfectly, IMO, because you already said you use the RX for long trips, which I perhaps mistakenly took to mean you don't need a bigger 'mini'van for long trip capabilities. We have a 5 and a Baja (not a WRX, but similarly fast) and despite LOVING the Baja I occasionally feel like taking the 5 to work. We have 2 kids under 6, but the wife often has another kid or even 2 more with her during the day.
On long trips (we have taken the 5 to southern AZ and back a couple times) the thing that gets to me about the 5 is not the space it's the sportiness. Sportiness is fun and nice but not for a 12-hour freeway trip. For that a big Buick is the best thing in the world because it's smooth and quiet. In any event, we've thought very hard about a trailer hitch to hold a cargo carrier w/sack or box in it for long trips. IMO they're better than roof racks for loading/unloading and for mpg. We'll probably get one if we start back up on long trips again.