I think you need to certainly do some confronting. P. Roe is correct in that multiple felonies are involved here (fake ID, and violating alcohol laws at a minimum, more if she doesn't have her own valid license).
However, vehemently I disagree with P. Roe about not respecting your daughter, at any age, but especially now. She's old enough to a) work, b) be charged with felonies and c)drive a car (aka an object that kills "about as many"* people as guns do in the US). She's not incapable of responsibility or independent actions (such as committing multiple felonies, circumventing procedures, and facing the consequences of such actions).
In fact, I feel that going through her things in your first attempt of showing her "that she needs to not keep valuables in her car" was wrong, due to the breach of trust that you are now discovering (in fact, speaking from experience, I can say that the breach of trust would have been WORSE had you found nothing, since there wouldn't be a possibly mitigating aspect of shame at being found out.
That is not to mention that you are failing to concider the fact/probability that your daughter has differing risk/reward tolerances and evaluations from you i.e. you are concerned about someone stealing her valuables in her car (or stealing her car, with the valuables in it). But she is either not as concerned as you are, and/or doesn't see the guaranteed cost of carrying her valuables back into her car as being worth the advantage if her car is stolen or broken into. You evaluation may be right, but the cost of a few hundred dollars is more than made up for by an improvement in this important life skill (and if it never happens, her risk evaluation may have been better than yours to begin with).
So how to proceed going forward?
Necessary Steps: Before anything else, you need to stop and think about what you are doing and why; you violated your daughter's privacy, trust, and property without a thought, and only after this bigger infraction was discovered did you see a problem with it. Think before you act (words of wisdom for pretty much every situation).
1. "Covert Intellegence": Replace fake ID where you found it, (possibly continuing with the badly thought out "take valuables from car to teach lesson idea"), and follow up with a general discussion about alcohol. This approach is the Churchill during the bombing of Coventry: you can't reveal your source that this is a problem, so you have to act as if this is a normal, general "you're getting older, so now we need to talk about things" talk. PROS: No fight or direct confrontation, smaller breach of trust (none if you don't carry out the "taking things from car" idea), no defensiveness. CONS: Doesn't deal with the evidence you found, liable to fail, she still has the license.
"Less Covert Intellegence": As option #1 in all respects, but do not replace the fake ID. PROS: She doesn't have the license. CONS: She may figure out that you took it, she can get another one.
"Staged Discovery": Continue with "take things from car idea", but stage the license in such a way that you "discover" it during your reveal. PROS: Can talk about evidence, remove license from her CONS: You are still not respecting her, will still have the conflict, she can get another one, and it depends on your acting skills.
"Tackle Bigger Problems": I would wagger that your daughter isn't sneaking into bars for the sake of drinking, she's doing it a) for fun with friends b) due to peer pressure. You can help alleviate both problems. Talk to your daughter (not accusing her of this incident, but again a general conversation). You can possibly help alleviate the first issue as well, by providing an alternate activity (that THEY enjoy!). If you have a garage, maybe they could hold a party there. If you are going out of town for a weekend, or even an overnight trip, you could explicitly allow a party to be held in your home (provided nothing is broken, and it's cleaned up afterwords. This could even be a lead into a drinking conversation. "Feel free to have a party when we're gone, so long as there's not drinking".
"Be an Adult, Admit Mistakes (Both to yourself and to your daughter), and Have an Honest Conversation": the best option, in my opinion. Show your daughter what it means to be an adult (a skill I find as I get older that many actual adults lack). Do NOT scream and yell, do NOT minimize, deflect from or in any way trivialize how much you've messed up. Do be calm. Do mention that you love her (not as a lead in to another point of attack, as in "I love you, but" or "Because I love you, I'm punishing you by", but as a stand alone statement. The statement is enough to stand on its own merits. In fact, I would have two conversations, completely separated, ideally one on a given day and the other on the next day. Do include your spouce, if you feel she can stick with and follow the above advice. Realize that your ability to punish is now trivial, and talk not of punishment but avoiding punishment. Don't position yourself as the punisher; she has much bigger problems than you, namely the government. Talk(not yell) of potential consequences. Fraud and forgery convictions can block employment in many sectors such as finance, administration, computer science, education, medicine and government? What does your daughter want to do? How can this compromise her ability to do it? What about drunk driving? Underage laws? Does she want to risk fines and jail time? Research with specific penalties in your state are possible plus here. She's nearly an adult (18), at which point any convictions would be on her permeant record, not a minor one. Acknowledge that you WILL most probably getting emotional at this time, and remember to keep your emotions in check. Remember that she's not a little kid that you are monologging at; she's a less experienced person MAKE SURE that you pause, and give her a chance to speak as well, and LISTEN to what she says.
*Whether more or less depends on the year, among other factors. I don't want to get into an argument about this, the point is the car is dangerous, and your daughter is at the point where society views she can be trusted with it.