well, if you go that route make sure everything maintenance wise has been done to it. all the wear and tear parts cost a loooot of money. Brakes, tires, spark plug change, PDK fluid change @60k etc.......... just going in for a big service cost you easily 2-3k. (thats without brakes and tires)
Problem is you can't really go independent cause they don't have the tools nor the interest to work on it. if you want you can PM me for more information.
Also make sure that everything has been replaced with Porsche parts, if the Dealer bought it from an action it was most likely trash and they fixed it cheap. run the history on the car (not Carfax) tell them to print out the History in the Porsche Service System, it will show you all the repairs (warranty/customer) performed. most importantly if it has been flagged by Porsche NA for substantial damage. if the car doesn't have a history it most definitely has an issue (flooded, etc.) don't believe if the guys tell you it had only an minor accident. i know from personal experience that even Porsche Financial / insurance clears a title to have a better resale value on their cars.
DO NOT buy a repaired vehicle, again DO NOT buy it. in the US there are only a few people who actually know how to repair the Aluminum and Magnesium chassis. And don't think the Bobby Joe repair shop around the corner has the tools or people to do it.
the warranty part is less important in my view, the car is pretty solid. it is an amazing car and totally underrated. as long as they shop or previous owner/lessee didn't skip on the service (which they most likely have, due to horrendous cost) or warranty repairs you should be good for a long time. the car will break down due to faulty control units or sensors way before the engine, transmission fails.
the technical part of the car is bullet proof, the electrics is what makes the car stop some years down the road. but that an issue with all the cars on the road nowadays.