Subaru Impreza WRX STI, Is it worth the $$

[gmrankin]

I bought a new car last year (Toyota Corolla XRS) and am overall happy with it, but i would really like to have a true sports car.

One catch, i need the ability to put a car seat in the back, so that rules out any 2 door.

I have seen some 2004's in the mid to high 20's which i can handle, but i don't know if it is worth the extra money (about 15K) for this car. My current car is fairly new, has an extended warrenty on it out to 80K miles, gets good gas milage, and i own about 12K on it as of right now.

Is the speed worth and increase in car payment, insurance and gas worth it. Whats my move?