So I just bought a really clean 04 D2 which seemed to be in great shape mechanically. I left the dealership and drove home for 2 hours without a problem until I got about a mile away from my house. I was driving on a windy road and a stop sign snuck up on me so I had to brake relatively hard. As soon as I became stationary, the car shut off. I then turned the key and it started up immediately. After a few minutes I wanted to see if it would happen again and braked super hard and the exact same thing happened. Any ideas?

 

Check your vacuum lines.

 

Could the inertia switch be bad?