it all boiles down to common sense really? buying any car is an expense so dont just look at the pictures and bid!
if the seller puts paintwork ok what does that mean? is there scratches or dents or chips in the paintwork? is it faded, somepeople love there cars and some people just fuel them up and go,
so to some people paintwork ok could mean its all the same colour? but to some they would say needs work and touchup,
ask every thing you can if it hasent been coverd in the discription,
does the engine use oil or water? any clunks or bangs from driveshafts or suspension,
but most important test drive the thing!
if somebody is used to driving round in a old wreck even the worst car could seem good?
i even know somebody who brought a car without seeing the engine because the chap said the cable was broken!
check the buyer has the log book and mot if applicable and everything number wise is as it should be,
the best way to find a genuine seller is when you phone up say i,m phoning up about the car?
if they responsed with which one the chances are they are a dealer pretending to be a private seller,
most of all ask and have a good look around and if indoubt walk away,
good luck and keep smiling.