Teenage drinking is wrong...parents should not be giving their kids mixed messages. Yes the kid did partly the right thing by calling home and letting her parents in on the situation...but she did the wrong thing by staying at a party where there was drinking in the first place. She should not be kicked out of the house.
The parents definately had the right to take that car home and have the right to take the car away if it is theirs. If the car is hers than she can very well assume responsiblity of the insurance payments and maintenance.
She is going off to college (if she is already dabbling in underage drinking then you know she probably will be doing so in college where she will have the opportunity and more freedom to do so) and should be fully counseled on the consequences of drinking. Depending on what her major is, if she gets a DUI or underage drinking arrest it very well may lead to her not getting a job in the field of her chosing or worse yet, being called into the deans office and being told that she will have to change majors because of the arrest or she is out of school.
She should not at this point have a car at college.....that way at least you know she and others will have less of a chance to be harmed from her drinking and driving.
I have a DD majoring in education and the education majors (and there are some other majors also in this category) at her college are told, point blank, you get an arrest for any underage drinking or DUI you are OUT the next day from your education major and any other major that carries that stipulation (such as law enforcement, etc).
So it's simple...you counsel kids on the right thing to do (regardless of the fact that you may or may not agree with the law as it stands, it is still the law and we/they should be obeying it) and the consequences of not thinking before they act and then you also add to that "I don't bail you out of jail" and I don't pay fines or court costs. We love you, please think before you act, do the right thing, and have a great college experience.