During a DUI stop or any other police encounter in Virginia you are free to complain and criticize the police under the 1st amendment to the US constitution but just this freedom of speech can be taken too far. Threatening a police officer can be obstruction of justice in Virginia and if your criticisms become so extreme and aggressive that they appear to be calculated to provoke violence then it becomes disorderly conduct. Both are crimes. Additionally, just because you have the freedom to criticize the police doesn't mean that you should. Especially in DUI/DWI cases if the driver is overly nasty and vocal this is sometimes interpreted as evidence that the driver is an angry drunk. You can a right to remain silent that might be more helpful in most cases.
If you have been charged with a crime or traffic offense in Northern Va. call Nichols & Green pllc for a free consultation at (703) 383-9222.