If you get stopped by the police and they suspect that you’ve been drinking, first thing they’re probably going to do is ask you if you’ve been drinking and that’s when you should exercise your right to remain silent. That can’t be used against you in court; it can’t be used as evidence against you. If you admit that you’ve been drinking, they will use that as evidence against you and they will probably detain you further.
Now, if you refuse to answer the question they may detain you further anyway and ask you to step out of the car. If they do, you should comply. They may ask you to do some tests like a field sobriety test. You can comply with those if you want; you can refuse those if you want.