Auto insurance giant Allstate claims in a new federal lawsuit that it fell victim to a racketeering conspiracy involving six metro Detroit patient treatment clinics, an MRI center and a medical transportation company that Allstate says acted together and made millions by abusing Michigan’s no-fault insurance system. Some of the clinics received help, the lawsuit says, from tow truck drivers and auto repair shop workers, who were supposedly offered kickbacks by middlemen such as $500 per patient referral. Other patients were illegally solicited to visit clinics just days after their car crashes, according to Allstate, by individuals who called up and claimed to be with a Southfield-based law firm.