[deepdog]

You don't have to not leave it in the car, you should just cover it up or hide it.

If you have a blanket in the trunk then hide your computer under it if you have to leave the car, or put it under the passenger's seat.

[dredmorbius]

Some equipment (e.g.: Bluetooth-enabled electronics) literally advertises its presence even when concealed. I've heard stories of thieves canvassing car parks in up-market areas with Bluetooth detectors and swiping Apple devices in particular.