find a jobber close to you that deals with PPG or Dupont and have them do the computer match deal on your car. It's pretty accurate. Most jobbers can put paint in spray bombs these days
This is the only way you'll get a true match, as they can account for aging and fading of the paint. You'll need to either take the car or a panel that they can use to match. I've done this a few times and always been happy with the results, can't say the same for buying premixed cans.