Well first, that it is actually a Cobra. Lots of clones out there. Take a look at the VIN. If the 8th digit of the VIN is not a "D" then it isn't a real one no matter what he says. Make sure that the crabclaw wing and 94/95 Cobra specific decklid are still there (3rd brake light is an LED strip in the wing, the decklid has no 3rd light) and all the other Cobra stuff is there too.
Besides that its pretty much the same as any other Mustang to buy. Looking to make sure all mechanical stuff is up to par, condition, rust etc...
2000 Mustang GT Steeda #0048
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.