Thinking about buying a car from a friend, standard 2001 Mustang v6. He is selling it for really cheap and I'd be stupid to pass it up. When asking him what is wrong with it he said nothing besides it jerks a little bit around 20 mph and its annoying when driving slow (I live in a high traffic area). When inquiring deeper about the jerking he said it was fine until he changed the transmission fluid. So I am thinking he might have put the wrong fluid in the car and I might have to flush it and hope all is good? What do you all think? What else could cause a low speed jerking? the car has 152k miles on it and besides that there is absolutely nothing else wrong and for a $600 offer I want to jump on it. I cant afford a new tranny so I hope its not that. Thanks all in advance

 

Auto or manual?