[Christien]

This place is a good place to start, compared to, say, eBay. You'll find a higher %age of honest, trustworthy people here. That's not to say everyone is, just more here than ebay or craigslist.

That said, there's no substitution for a pre-purchase inspection at a qualified shop that the current owner doesn't use. Expect to pay between $300 and $400 for a full inspection, including leakdown and compression tests, and results will be sent to you directly, not via the seller. First ask the seller for recent service receipts, so you can see what shop(s) he deals with. Next, locate a shop nearby (ask here for recommendations) and choose one other than the shop(s) the seller has used. Then call them and give them the seller's contact info to setup an appointment for inspection. Any seller that refuses an inspection is suspect - walk away. The inspection will tell you everything you need to know. Personally, I would feel confident buying long-distance, sight-unseen, on the basis of inspection results. In fact, I will be doing so shortly when I decide which car.

Good luck!