Your wheels appear to be 996 18" Turbo Twists. Hollow spokes if they are from a Turbo, solid spoke if they are from a C4S.
Look near the valve stem, the offset in mm, and the width in inches should be marked. If that fails, take a look at the inside of the wheels, the numbers may be there.
My guess is 18x8, 50mm offset Front, 18x11, 45mm offset Rear.
max
__________________
max
|