Thanks to Danny from the 808 state (Hawaii for those not in the know) for sending in pics of his camo green Scion xB.
In order to fill out those fender flares, he went with a set of 15×8.0 WORK XSA-02C Wide in White (WHT) Finish.
Just for reference, here are the differences between the WORK XSA-02C series:
WORK XSA-02C: 20″ & 19″ Step Rim / 20″, 19″, 18″, 17″ Full Reverse (17″ widths 7.0″ – 9.0″)
WORK XSA-02C Mighty: 17″ (widths 5.5″ – 6.5″) / 16″ (widths 5.5″ – 9.0″)
WORK XSA-02C Wide: 15″ (widths 5.0″ – 8.0″)
(Source: krp2nyte)