Whats the problem with taking off the front "panel"?
You need the bumper off to do both, and the only other thing you need to take off for the S3 core is the slam panel and dis-assemble the A/C from the cooler itself.
The good thing about the S3 core is that it has OEM appearance, and it wont restrict air to the A/C core or the OEM Cooler, and it does give 20% decrease in inlet temp over the OEM core.
Also, you could have an S3 core and a cat back exhaust for the price of a Forge unit.
I have an S3 core, and it upped boost upon spool and saw 20% drop in inlet temps overall.