First, I used eBay's geographical radius tool to find local cars.
Then, after I browsed what was available on eBay, I went to the seller's location and test drove the car; many cars which sounded good on eBay were flawed in some way.
Finally, when I found a car I test drove and I liked, I told the dealer that I would buy it outside of eBay at a negotiated price. Because the dealer had a real person who would pay in cash, and because the dealer did not have to pay eBay fees, the dealer agreed to make whatever repairs were needed to pass a Pennsylvania State Inspection (the most obvious being a broken passenger side rear view mirror).
I bought a 1995 Honda Accord with 120,000 miles three years ago. It has 155,000 miles on it now, and the powertrain has not required any major repairs. I got a keeper which gets good gas milage.
The dealer offered me powertrain insurance, and I declined. The first indication it was not a good deal was the copy of the details of the insurance I received had about one inch of the right hand side of the printing cut off. In reading what I could of the details, if, say, the timing chain needed to be replaced, the insurance would not pay for the labor involved in taking out the radiator and the other parts needed to access the timing chain, nor with it pay for the labor to replace those parts when finished.
I had previously worked as a computer programmer for a firm which sold powertrain insurance through dealers. Half the money you pay for this kind of insurance goes to the dealer as commission! Also, you paid higher rates for Pontiacs for some reason. And you paid much higher rates for a Jaguar.