long story short, selling a 97 civic w/ 120K miles for $3k on craigs list.  about 300 below blue book on craigs list so its a hot ticket.  ive had this car for 4+ years and its run like a top, never a problem except a cracked exhaust manifold that was welded for less than 50.
so dude comes by to look at it in a nicer car than i am selling and asks to drive it, and if i would answer his wifes questions while he's away.  i screwed up and trusted...
dude returns a few minutes later and asks to drive it up the street a bit more.  he proceeds to drive it a couple hundred yards up and back, i am like wtf?  he gets out and says he likes the car alot and wants to see the engine and we do.  i pull the dip stick i had pulled an hour earlier and now found water in oil froth!
i start shatting myself thinking now i have a car with a blown head gasket and there goes my guard LSD for the 911.  i am moaning the blues as dude offers me $1K of the 3K i was asking, says he can fix it and wants to make a fair offer..  he proceeds to up the offer to 1500, 1700, and then finally $2K over the next ten minutes.  at this time i start to smell a rat as he is so eager to offer me cash money for it.  so i pull the radiator cap off expecting to see the quart high in oil/water on the dip stick missing from the radiator & its full to the top as green as prestone recommends.  now i suspect he poured water in the oil around the corner and needed that last 200 yards to get it the last bit mixed up and i tell him so.  he kinda mumbles, studders with a dumb ace look i had yet to see from him.   at that point he continues with the offer of two geezels and i ask him to pack his kids and wife up and get off my property.  
so heres how i see it--
i caught the guy red handed and did not fall for his BS, and should have throttled him, or at a minimum released the hound on him and the family.  i also learn no more unescorted test drives.
i sent dude & his 2 grand away for a honda WITH a blown head gasket and i will never sniff that much for again.  i am dumb.
i will have to change the oil and see if i can recreate the water/oil intrusion, do a compression check and maybe drain the radiator. maybe out smarted myself?
have you heard of this tactic in devaluing a car?  dude came with his wife and kids to disarm me to some extend.  and oh yeah, i had pulled the dip stick out after the test drive before him an hour earlier and no froth. 
what do you guys think?


 
T$