If you mean an impounded vehicle, it probably depends on the locality, but here in my city, the police department sells siezed vehicles once a week at an auction.
you can ask someone at you local police station or Google "police impound"
Contact the impound lot or police dept to find out what to do.
you have to buy it
This question needs to be rewritten. A president does not impound people or things. Police departments impound items.
You go and pay the impound fees.
private property impound - possibly due to parked in a private lot
yes
Assuming we are talking about a police impound lot, it will depend on the laws of your state. When a police officer stops a car in your state, whatever paperwork he will ask for during the stop is the same that you will need to show to the impound attendant to get your car back.
Yes
ask your friend
Call the local police impound facility. Here in my city, it's downtown at the jail facility. If you don't know where it is, call a local precinct. I'm sure they can tell you.
Yes, if the offence has been committed, and it calls for a tow and impound, even if you are in the car and it is illegally parked, say good by