Let's take your average mall or strip mall. There are plenty of people coming and going every few hours. But, some cars stay in the parking lot much longer than others. Not only that, but those same cars are pretty much every day. Why? They belong to the employees who work there.
As with any good crime, it's all about opportunity, predictability, reward and level of risk involved. (Or means, motive and opportunity, but that's more about spontaneous crime.)
Car theft, or burglary from cars is pretty low risk in this case.
First, you have plenty of time for planning. My method of operation would be to cruise the aisles, as if I was looking for a parking place. But.. what I would actually be doing was videotaping every car in the parking lot. I would do this on a number of occasions, especially when it's busy, but also in the off-times. From this, we can establish patterns... which cars belong to employees, what shifts they typically work and in many cases, if they have a security system, just based whether or not there's a visible blinking light... often in the dash, or near the door locks in the case of VW's (and Audi's?). Of course, also be on the lookout for cameras or security guards. Cameras may dictate what kind of crime you can successfully get away with. Security Guards are easier to deal with.
And let's face it... people who work at the mall often have crummy cars with really nice stereos, lots of CD's and other expensive stuff in their car.
So now that you know which cars are employee cars and which cars are the best targets... based on where they park, if they work until closing, stuff like that.
Now, you have a couple of options. The best bet is to park next to one of the cars you intend to steal or break into. Then, if there are human security guards, you can divert their attention by setting off your own car alarm a few times. When they come to check it out, they realize it's just an overly sensitive car alarm and after that are less likely to pay as much attention to the general vicinity of any future alarms, even if they're a different car. (Though hopefully you'd go after cars without alarms because there will be plenty of marks that aren't armed.) Of course, the other diversionary tactic, if you have a large crew, is to stage something on the other side of the parking lot to draw all the attention away from you.
Parked next to them, you can pretend to struggle getting packages into your car to hide the fact that you're actually breaking into the car. Or, you can put fake AAA magnetic panels on your car and no one will even pay any attention to you.
Risk... minimal. Opportunty... great. Reward... great. Predicability/patterns... check.