Not very clear what the issue is that has led you to ask this question. Take it you mean Enterprise as in the car-hire company?
On the face of it, why would you be mad to buy a low-mileage 07 car at what you think is a good price - I take it the car has a full service history is clean like a new car and seems to be in pristine condition?
Enterprise also seems to have given you a guarantee with the car - part of which is the offer of a replacement car should your's be off the road during a repair....
Sure, ex-hire cars mightn't have the best reputation, having normally had many different drivers, but that would explain the good price. I can't really see what the problem is. Why have you got concerns?