Pozican, I was with you...didn't get that post. Anway, welcome to the forum and Porsche ownership. Hopefully someone has told you about the necessity of maintenance on these cars. Timing belt, water pump, and rollers should be done as soon as possible if you do not have maintenance records on them to show how old they are. They are good for 30,000 miles or two years. Don't miss it as it's an interference motor and if the belt slips or breaks, you will put a valve into the piston and have major damage. I see you have already been told about clarks-garage.com but here is another site that has some useful information.
http://www.connactivity.com/~kgross/FAQ/944faq05.html
If you want to read more, change the 944faq05 to 944faq01 and so on. You will find many knowledgeable and helpful people here and it will make owning this car a much more enjoyable experience.
The rear hatch also has another common problem that causes it to squeak. The window is glued into an aluminum frame and the hatch is supported by that frame. The glue doesn't hold forever and will make the window move in the frame and squeak and LEAK. There is a post by me on here asking how to fix this problem, I think it was about a year ago. A guy named Tim Hancock provided most of the information to me and hopefully it will help you to if that is one of your problems. On mine, I could see a gap between the frame and the window. Look carefully as it isn't real apparent at first.
Good Luck with the car and welcome to the forum.