A 1998 model with 500 miles should be a Big Red Flag!
I've owed an E-M and worked on several others.
Go slow and check it over very carefully. Get someone who works on Cobras to look at it.
I've had guys bring me a Cobra he paid $38,000 and spend $10,000 to make it save to drive. And I work cheap.
You will spend money on things you want to change but items like brakes, rear end, suspension, motor or tranny are not things you expect to repair or replace if you paid a premium price for the car.
This cars sounds like one built to flip.
We had a local guy that did that with Cobras. He sold a lot of problems for good money.
