Unknown to many people, major cell phone providers also offer roadside assistance. Typically, the providers use other clubs such as AAA for their towing networks. But monthly fees are low and they offer all the basic services, such as towing, lockout assistance and key replacement. These programs require close scrutiny, though.

"Cell phone providers' roadside assistance makes sense, given the popularity of OnStar," says Reed. They also offer the most frequently used services such as towing and lockout help. For example, Sprint's Roadside Rescue is $4 monthly per phone line, which includes basic service such as towing. Verizon's is $3 monthly and includes towing up to 10 miles, fuel delivery and lockout service. AT&T also offers limited roadside assistance.

The downside: Your cell phone must be with you when your car breaks down because coverage follows the phone. Towing miles are also limited, which may mean unexpected out-of-pocket expenses.