You call a tow truck and are brought to the nearest service station. The mechanic on duty says you need a new alternator, which will cost you $500. You usually like to get a second opinion on repairs if you can, but towing the car to another shop is going to take more money and time.
You don't have much of a choice but to get the repairs, At the same time, you don't want to get ripped off. Now, with the help of a little 21st century technology, you can quickly and easily double check any mechanic's honesty.
Check repair costs online
RepairPal.com launched in 2007 to "provide drivers with the most accurate, unbiased and useful car ownership information available," according to its website.
RepairPal can find out the estimated cost of repairs for any make or model made after 1990. You choose your zip code, car details and then select a specific repair.
In moments, you are given an estimated cost or repairs, broken down by parts and labor and what you should expect to pay at an independent shop versus a dealership.
There is also a detailed explanation of what the specific problem is, what causes it and things to be aware of when fixing it. The site is run by automotive experts and says it is not affiliated with any automobile manufacturer, dealership, parts provider or auto repair facility.
The site also has an extensive auto shop directory and expert insights and advice from certified mechanics.
The site also provides a centralized location where your records can be stored for the entire ownership cycle of your vehicle. A coming feature will send you emails that will remind you of an upcoming oil change or scheduled service.
RepairPal also has an iPhone application that can be downloaded for free so you can get accurate auto help anywhere you have cell phone service.
Let your car tell you what's wrong
A device called the CarMD can take things even a step further than by giving you a quick diagnostic readout of your car's engine.
For around $120, you can buy a CarMD and no longer have to rely on your mechanic for an accurate computer reading of your auto.
Here's how it works:
Every car manufactured in the United States -- foreign or domestic -- has a small plug-in called a 16-pin data link connector, which is usually located under the dashboard on the driver's side. By plugging in the small CarMD device into the DLC, you can get quick computer readouts of your car's engine.
The first step gives you a quick read of the engine's health by displaying a green, yellow or red light. Green means good, yellow or red means something is wrong and needs further investigation.
If you get a yellow or red readout, log onto the site and plug the CarMD into your computer's USB port to view the cause and probable cost to fix it. CarMD doesn't cover every problem your car might have, such brakes or batteries, but it does cover most of them.
"Basically, (CarMD) covers anything related to engines, emissions, the transmission or the oxygen sensors. It's about 80 percent of the systems on the vehicle," said Kristin Brocoff, product manager for CarMD.
Any time your check engine light comes on, you can run a quick CarMD check before you even bring it in to a repair shop. That way, you will know the problem and probable cost before your mechanic does, and the chance of you getting ripped off should lower significantly.
You can also get readouts of the engine's health before a long road trip, check the health of the engine of a used car you are thinking of buying and smog test your car.
Other helpful resources
Finding a good, trustworthy mechanic is sometimes a difficult thing, but there are a few resources that can help in the process.
The popular national radio talk show "Car Talk" has a database on its website called the "Mechanics Files" of 16,000 mechanics that have been recommended by the Car Talk community.
The website Angie's List also has an extensive database of mechanics that have been rated by its users.