Victorville Motors, one of the oldest car dealerships in the Victor Valley, has invited Fiat to join its Chrysler, Jeep, Dodge and Ram family. On Monday, Stephanie Harris, senior account executive with the Modera Inc. advertising agency in Irvine, said the new "desert Fiat Studio" dealership should have a grand opening sometime after Jan. 1. "Victorville Motors will probably have a soft opening sometime before the first of the year," Harris said.