Hi, I have a 98 mustang that's been down and I miss it and want to fix it. Just havnt because of moneys but anyways, someone was driving it fast on the freeway, when getting off at exit he says the car just stalled on him. the car turns on alright, it struggles a bit but it used to take a second before anyways. the weird thing is that its fine but once you put it in drive or reverse it just turns off. no noise with it really. a "mechanic" came and took a look, he replaced some sensor and said all was well, then I asked if he had tried MOVING the car. It shut off and he said its probably the transmission. what are some of the issues it could be and price range for the fix do you think?