2006 CS with backup sensor cutouts???
 

Has anyone ever heard of anything like this. Car looks very clean, but it has these knock outs pre molded into the bumper, but the car doesn't have BU sensors! Aftermarket??

Car could have been hit in the rear and a used bumper might have been sourced instead of a new correct one.

Car has clean carfax. I went and looked at it and it does have parking assist! Was this an option in 06?

Yes, it was available as an option then - though I see very few Caymans with it.

FYI just because a car has a clean carfax does not mean there has never been work done. Any wok that was not reported to the insurance company and was payed for out of pocket will not show up on a carfax. Also it takes 60 to 90 days for an incident to show on a carfax.

I am very aware. Car has been in dealers possession for 4 months, so all entries, if any, should show. My original thought was that they put an aftermarket bumper on the car, but it looks very stock and clean.