At some point or another, you've probably half-heartedly swung your car's passenger door closed, only to see the "door ajar" light come on once you're on the road. In some cases, this can even result in the door swinging open while driving. Slamming the doors shut is one option, although Slamstop is designed to be a quieter alternative.
The Slamstop device is installed within the door panel, and senses when the door is almost closed. It then softly pulls it completely closed, and latches it securely. As an added bonus, the door will retract if the sensor detects there's an obstacle in the way of the door closing, so childrens' fingers are safe from being closed on.
If it sounds familiar, it's likely because Slamstop has been featured in some higher-end automobiles over the past few years. It's now newly available in the US as an after-market kit, however, for any make or model of vehicle (including those with sliding doors). Pricing for all doors of a four-door car ranges from US$800 to $1,000, installation included.
You can see it in use, in the video below.