What do a brand-new Mercedes-Benz and a beat-up old pickup truck have in common? Besides four tires and engine, they're both useless if they break down and leave you stranded somewhere.

When that happens, you'll be glad you have roadside assistance from an auto club. Such programs provide services like towing, flat tire repair, lockout help, battery charging, fuel delivery and in some cases even mechanical repairs [source: Autoroadservice.com]. There are lots of roadside assistance programs available from AAA, AARP and even from Wal-Mart, just to name a few.

Typically, the consumer purchases roadside assistance that's good for one year. Members pay up front or can make installment payments throughout the year. As with most things in life, you get what you pay for. The programs vary widely in how many miles they'll agree to tow your vehicle and the extent of services offered, too. Roadside assistance programs can run anywhere from around $36 to $100 a year or more, depending on the level of service provided [source: Consumer Reports].

For example, AAA's basic service costs $52 a year. That includes towing of up to three miles (4.8 kilometers), but asks you to pay for fuel and doesn't include fancy extras like RV or motorcycle towing. For a little more ($82 a year), AAA's Plus service will tow your vehicle up to 100 miles (161 kilometers), and if you opt for AAA's $105 service, they throw in perks like car-buying assistance [source: AAA Texas].

You may not want or need all these extras; however, it's important to cover a few critical bases, like having 24-hour roadside assistance and a policy that covers drivers, not vehicles. Also remember that insurance companies keep track of roadside assistance calls and an excessive number of calls for help may mean higher premiums for you in the future. It's also a good idea to keep in mind that your policy may not cover every emergency, like a snow-grounded car or a vehicle stuck in a flood [source: Blackwell].

Before you decide to invest in roadside assistance, make sure you don't have this coverage already. Many manufacturers offer roadside assistance with a new car purchase, as part of the vehicle's warranty. These services usually last the duration of the car's warranty -- typically anywhere from three to five years. The details will be listed in the paperwork you received when you signed for your new car.

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