So we both have silver '06 997s, you with 18s, me with 19s. Each wheel size seems to have its pluses and minuses. The 19s look good on the car but, for me, the ride feels a little hard and the handling somewhat forced, rather than natural. For you, the 18s ride and perform well, but leave a little too much space around them in the wheel wells. What will the spacers do? Are you going to drop the car? Enjoy.