This one should be pretty simple, just don't get cocky. Even an easy job can go wrong.
Here's how this is gonna work. We're loading the car up with our gains, while the police are responding to the alarm. Whenever you think is best, pull away and we'll stop loading. Go sooner to give yourself some distance before the police arrive. Go later, and our score will be bigger should we get away at all. Once we lose the police, stay low, head for the safehouse, and keep an eye out for any cameras. They'll get the police back on us, so be vigilant.
Remember, our safehouse is the old mansion off the airline highway. Just be sure not to lead the police right to it...