Some time ago I wrote up with photos an example of an aftermarket tank and it's many problems.Fortunately I caught them before running the engine. If the tank fails catastrophically when you are on the Freeway it could be a really na$ty day for you and your car.
Pelican has one from an "OE Supplier". That may be worth investigating?Maybe JFP knows about it ?
2001 Porsche Boxster S Convertible - Radiators - Page 4