(NAPSI)—When your vehicle’s brakes wear out, they probably “chirp” or grind. When your tires become worn, you can see the loss of tread depth.

Failed headlamp? Worn wiper blades? The evidence is right in front of you.

But how do you monitor the condition of safety critical parts that are largely “invisible” beneath your vehicle’s chassis? Shock absorbers, for example, play critical roles in protecting your driving safety by keeping your tires planted firmly on the road, which in certain driving conditions can help you stop sooner, maintain more precise steering control and improve vehicle stability. That’s why having your suspension inspected at least once a year is vitally important—you might not be aware that your shocks and other key safety components are no longer doing what they’re designed to do.

Ask About a Guarantee

Some leading automotive parts manufacturers have established money-back guarantees to help demonstrate the importance of replacing worn components. The Monroe shocks and struts brand, for example, now promises consumers they will “Feel the Difference” in ride and handling performance following installation of select new Monroe shocks and/or struts or get their money back, plus labor and alignment (if applicable), during a risk-free 90-day or 1,000-mile trial period.

“Consumers have the right to expect a noticeable, positive difference in vehicle performance following a repair,” said Mark Boyle, director of marketing for Tenneco, U.S.-based manufacturer of Monroe ride control products. “Our new Feel the Difference Guarantee is designed to offer the consumer assurance that they are making a wise investment in their vehicle. It also helps promote confidence and loyalty in their relationship with the repair provider.”

Because shocks and struts often wear out very gradually, the slow degradation of ride and handling precision can be difficult to detect—not unlike the gradual change in your eyesight. But, just as a new vision prescription can have surprising benefits, vehicle owners who replace worn shocks and struts or other undercar components can experience dramatically improved ride and handling. New ride control parts can also reduce chances of abnormal wear of other components, including tires.

“After a ride control repair, many consumers are amazed at the difference in their overall driving experience,” Boyle said. “A guarantee like ours essentially is an investment in educating consumers about the ‘invisible’ parts that help keep them safe. And it helps ensure they get quality products from a supplier they can trust.”