[tboyer]

Hey Michel, welcome to the forum, sorry to hear about your bad luck. Unfortunately many used Boxster's are sold with some "hidden" issues, the coolant/expansion tank located in the trunk including the hoses and water pump are common reasons for leaking coolant. The leak may be under the carpet in the trunk. Click here for a post I started with a similar issue

Regarding the warranty, we had some traffic on that topic today, click here to view traffic