fr-s tow hook plate relocator - Scion FR-S Forum | Subaru BRZ ...

Pretty sure it is 60" from the ground and mounted vertically.

http://www.dmv.ca.gov/pubs/vctop/d03/vc5201.htm

5201. License plates shall at all times be securely fastened to the vehicle for which they are issued so as to prevent the plates from swinging, shall be mounted in a position so as to be clearly visible, and so that the characters are upright and display from left to right, and shall be maintained in a condition so as to be clearly legible. The rear license plate shall be mounted not less than 12 inches nor more than 60 inches from the ground, and the front license plate shall be mounted not more than 60 inches from the ground, except as follows:

http://www.merriam-webster.com/dictionary/upright

Definition of UPRIGHT
1
a : perpendicular, vertical b : erect in carriage or posture c : having the main axis or a main part perpendicular <upright freezer>