Regret not ponying up for that OnStar subscription for your last car? A startup called Automatic promises to provide most of those features (and a few extra) with an iPhone app and a hardware dongle that plugs into your car’s diagnostics port.

The device performs diagnostics, lets you turn off your “Service Engine” light, provides fuel-saving tips based on your driving habits, remembers where you park (and where you drove), calls for help in an accident and more.

The device (expected to ship in August) costs a one-time fee of $69 and connects to a companion iPhone app via Bluetooth. (An Android version is planned; Windows Phone and Blackberry users are out of luck.) The company says it works with virtually every gasoline-powered car sold in the U.S. since 1996.

If Automatic lives up to its promise, it could be huge. More information, including a link to pre-order, is on the company’s website.

Here’s Automatic’s promo video: