We get less feedback on Porsche than an enthusiasts' site such as Pistonheads, but do have: www.honestjohn.co.uk/carbycar/porsche/911-997-2004/ You can't test drive it unless you have insurance to do so or the vendor gets it for you via someone like www.dayinsure.com/. There's no warranty from a private buyer so you have to ask pertinent questions such as "does it have a full Porsche service history", "has anything ever seriously gone wrong with it?" "has it ever been over-revved?" "are you aware of any faults at all with it." That then makes it a Breach of Contract if the vendor misleads you in any way. How to pay is up to you, but whenever I sell I want to do it in a bank where it effectively becomes a cash transaction that cannot later be revoked.