I'm one of those guys that knows just enough about cars to get by. I can fill the fluids, tell when the engine is running rough, when the tires and brakes need replacing. And that's about it. The Check Engine light comes on and it's off to the professional. Which is where things get sticky.

As guys, it's assumed it's in our genes to know all about cars and how to fix them. But many of us don't know enough to sound intelligent, let alone diagnose and repair a major problem. And without in-depth knowledge of ever-increasing technology and engineering, you (and your wallet) are at the mercy of your mechanic.

SAM (for Smart Auto Management) is a new technology that's out to change that. And give you the ammo you need to keep your mechanic honest.

Available in just a few southern states and in parts of California right now, SAM is an 8-foot tall kiosk that looks like a high-tech gas pump. In 10 minutes, it'll run a complete diagnostic of your car's systems and report back any problems.

How? Since 1996 every vehicle in the US has been fitted with an onboard diagnostics system, or OBD II, that collects and stores info about your car's ABS brakes, computer system, engine, exhaust, and any other electrical, mechanical or computerized parts. The OBD II stores this info, and if it becomes serious enough, triggers a warning light. Service centers charging $85 and up to run a diagnostics test are accessing this info. So does SAM. For $15.

After swiping your credit card and scanning your VIN code, you'll get a diagram showing you where your car's OBD port is. Plug in the wireless device and in about 10 minutes you'll get a printed report, in both plain English and industry terms (so the wrench heads at the shop don't try to double-talk you), that'll clue you in to any existing or pending problems, your car's warranty status, as well as any technical service bulletins or recalls on your car.

Is it perfect? Of course not. Nothing is. There's a list of cars SAM doesn't play nice with (including Mercedes-Benz, BMW, Isuzu and Kia), and if your car has had something improperly replaced or connected it may not be able to communicate with SAM completely. But for arming yourself against auto shop rip-off, or as a $15 insurance policy against a bad used car deal, SAM is a great friend to have.

www.iamsam.com for a list of locations.