An industry friend in Southern California, Mitchell Bailey, called to report a stolen bike, as well as to let his fellow riders know to keep an eye out for scams like this:
 
A woman named Alex Duarte (obviously a fake name), driving a Ford F1-50 champagne color with a license plate 5AFD767, came to Mitchell's house to pick up the bike she agreed to buy - a 2006 Suzuki RMZ450, vin #JS1RL41C062103733 - in the evening after the banks were closed. She paid with a fraudulent cashier's check that was so real-looking, even the police said they would've accepted it.

And upon further investigation, the police realized that the plate did not belong to that truck. 
 
If you have any information, e-mail [email protected] or the Riverside Sheriffs Department.  And if you have any other questions about the incident, call Melissa 951-926-0126.