What i don't get is why the guy would stop cold turkey from driving the car as soon as he found the leak? Honestly, does anyone do that? We all are guilty of continuing to drive till it gets so bad we have to fix it or just fixing it right away. It sounds like you will be getting a car that has been beat on and probably maintianed to the best of his ability, but his ability to maintain the car is no longer there. If i were in your show i would pass and be patient. Good luck.