Zipcar $($www$.$zipcar.com$)$ is a car$-$sharing club founded in Cambridge, Massachusetts, in $1999.$ The club members pay an annual fee and then have the opportunity to rent from a pool of available cars for a fixed hourly or daily rate. Zipcar is located largely in select metropolitan areas such as Boston, San Francisco, and Washington, D$.$C$.$ Members, called $$Zipsters$,$ make reservations for a car on the Zipcar website and then use an access card to open the vehicle. The vehicle has a $$home base$$ parking spot where the driver picks up and returns the vehicle. The club$$which operates in more than $500$ cities and towns, at more than $600$ college campuses, and at $50$ airports$$has grown to more than $1$ million members since its initial public offering in April $2011.$

The Zipcar website provides details on membership and mentions a $$8\mathrm{.}00$ monthly membership fee. A car can be rented for an hourly or daily rate. While the actual rate can vary, a car can be rented for about $$8\mathrm{.}00$ per hour, which includes $20$ free miles, or for a $$77$ daily rate, which includes $184$ free miles per day, and a charge of $$0\mathrm{.}45$ per mile for each mile over $184.$

$1.$ Identify each car$-$related cost as fixed or variable.

Items Fixed or Variable

Gas

Maintenance

Insurance

Parking

$2.$ Identify each listed item as a competitive advantage or challenge.

Items Advantage or Challenge

Entrance of competitors

Convenience

Sustainability

Rising cost of gasoline

Ability to cover fixed costs