They would need a warrant or permission from the owner of the garage or of the car or both. They could claim there was a risk the car would be driven out of the jurisdiction if they had to wait for a warrant.
It depends on what jurisdiction you are in. In many jurisdictions, police are legally permitted to enter a premises whenever they have "probable cause" or "reasonable cause" to suspect that there is an illegal activity in progress (for example, if they could hear someone being attacked). Some laws also may allow police to enter a house without a warrant if they are in the course of investigating a specific crime.
A warrant gives the police the right to arrest you at any time - that's what a warrant is. So it does not matter if you do or don't turn yourself in, the police have the right to arrest you if they have a warrant.
A search warrant allows the officers to enter and search your home or office, whatever is specified in the warrant. An arrest warrant allows the officers to take the offender into custody AND search the area where the offender was located.
If you suspect this you should go to the police.
Yes, they may accompany officers of the jurisdiction in which the warrant is being served and who will actually effect the arrest.
They have to have a warrant, or in some cases they need to suspect that someone is in imminent danger. Or they can conduct a search for weapons when they detain (note -- not arrest) you. They can also conduct an incidental search if they have Probable Cause to believe a crime is being committed.
Governor's warrant: Refers to a warrant issued by the Governor's office and used to extradite a wanted suspect from another state, where they are being held under arrest, in order to be returned to the warrant-issuing state to face trial for a criminal act.
Yes, there must be supporting paperwork defining the offense and the reason for the warrant application, prior to one being issued.
If the question is whether the police need to speak with you or interview you prior to arresting you on a warrant, the answer is no. If it was a requirement that they speak with you, anyone could avoid being arrested on a warrant simply be refusing to speak with the police. Police have an obligation to make sure they are serving the correct person (i.e. - the person named on the warrant) and to do so they will often ask questions first. If they already have a warrant for your arrest, that means that a judge already decided there was probable cause to believe you committed a crime. You might be interviewed after the arrest but if they have probable cause already there is no requirement for them to interview you prior to serving a valid warrant.
No because the car is your property unless they have a warrant
If the subject being detained is the object of an interstate extraditable warrant, they will travel to whatever state the detainee is incarcerated in.
You, as an individual, can not obtain an arrest warrant. The most you can do is make a report of the offense to the police and, if upon investigation, they determine that the suspect you name is the perpetrator they will either arrest them or THEY will apply for a warrant for their arrest. In some jurisdictions, if you witness an offense you may go to a Magistrate, Justiice of the Peace, or the court, and swear to an "information" which, if legally sufficient, could have the effect of having a 'summons to appear' (in court) being issued to the individual that you name.