I used an EBS baffle. The kit can be purchased on Pelican. It does need a bit of modifying (at least mine and others did). Maybe EBS has improved their design, but don't button everything up without doing some test fitting first.
CSS = Cayman S Sport
I forgot to mention you should purchase an extra AOS and take it with you to the track. If you blow the one on your engine, you'll have a spare and your w/e won't be over.
Others can respond about square tire setup. For some cars it's frowned upon because it messes up PSM, but if you don't have PSM it won't be an issue.