A good place to start your career, though a challenging job in many regards.
Pros
Enterprise is a great place to start your career, especially with the intern program. Other employers are frequently commenting on my experience with Enterprise and that it adds value to my resume/work experience. In many ways the mantra on the company's website that working for Enterprise is similar to an MBA program may be true. You do get experience with all aspects of the company, including many things you can take with you to future jobs. You do get a good deal of flexibility when it comes to customer service; you can make many decisions in the name of customer satisfaction without an earful from management for your having done so.
Cons
Long long long hours. You're expected to work a 48 hour work week, and the vast majority of employees seem to work many more than this. Enterprise tries to supplement this with its "work/life balance" program, but it doesn't help much for the average employee. The company hires mostly new college grads specifically because they are more apt to tolerate such long hours and expected work on weekends, and many do. The path to promotion is there, as virtually all of the company's upper management started at the bottom. But to get there you have to jump through many hoops: not only the long hours, but many requirements such as sales of the company's protection products (the rental insurance everyone and their brother has told you not to buy). Even if you satisfy these requirements and are therefore eligible for a promotion, you have to wait for one to be available in your area or subject yourself to a long daily commute (all while working longer hours). Dealing with some customers can be challenging after a while, especially because the company's emphasis on customer satisfaction means it must be a priority even if the customer is outright unreasonable.