web usage reports after PAT to external scansafe web proxy service

Hi We recently put a  NAT /PAT  inside to outside interface (on ASA firewall) and port 80/http to 8080 port forward -direct to Cisco's scansafe proxy servers IP address on the web.
We  have some "exceptions" for http sites we dont want filtered - these are ok and also listed in the ASA firewall

We did this to solve a number of problems

1. Apple IPAD's - wifi - avoid manual proxy in browser
2 avoid manual proxy entry for all different types of browser
basically now proxy config is all in the ASA firewall.

Problem is now that due to the ASA NAT the scansafe reports show only the "outside" IP as the no1 user - basically the only user. - so now i cant get meaningful web usage reports.

Before with proxy ticked in users client browser - THe reports showed individual usage.
I want to keep what we have done on the ASA - I dont want to do a PAC file etc.

Does anyone know how I can go about getting the Scansafe to show individual web usage again? - something i can do on ASA?
  Thanks