Thank You for writing into AskPatty! A great place to start looking for replacement parts is a salvage yard. If you have not been able to locate side louvers by this method, there are many on-line parts stores that may carry this part. If you still have not been able to locate, the contacting of your local Toyota dealership parts department may be a final resort.
Hope This Helps!
A. J. Valle
〉 Answered on Jun 1st, 2012 by Amanda J. Pierce, MBA "AJ", Certified Mechanic, Project Coordinator; Primavera Scheduler at VIGOR Alaska Industrial Shipyard & BizzM3ch Solutions