Mike Atagi

Mike the Mechanic or Mechanic Mike is a human man and is Harry's mechanic throughout the series.

Overview
Harry hails him as a genius. Harry's car, the Blue Beetle, is continually recieving trauma in the line of duty with Harry battling the monsters and Supernatural bad guys.

Harry trusts his car, and depends on it. It gets him where he needs to go without his magic interferring with it's abilities as a vehicle. So Harry depend on a good mechanic that keeps the Blue Beetle running no matter how bad the damage.