Is a CPO Boxster S worth 4000$ more?

[Brucelee]

I have dealt with this from most angles.

Pros

Nice comprehensive warranty
Porsche dealer inspects car and repairs many items BEFORE they sell it to you.
Somewhat easier when getting repairs from dealer, as coordination of the warranty payment is a bit easier.
Feels better to have a CPO car.

Cons

Compared to a CPO program like Lexus, the Porsche program is a bit of a let down.
Porsche is weak on the documentation. Many here have complained of never getting any warranty paperwork.
Porsche dealers are a bit weak on the coverage knowledge.
Dealers are inconsistent with what is covered, leading to confusion.
Defiintion of WEAR items can get you.

At the end of the day, it is very subjective.