SQL 2012: Avoid "Extract Setup files"?

Hi,

I have a powershell script for our developers that handles a quiet-simple SQL 2012 install.  I have opted to slipstream from an update folder.  I currently have SQLServer2012-KB2723749-x64.exe and SQLServer2012-KB2723749-x86.exe in the folder (CU3).  I notice that the "Extract Setup files" takes a while.  I would like to reduce the install time if possible.  Is there a way to supply extracted updates so that setup can skip the extract setup files step? 

Thanks, Randy

Randy in Marin