do you still have the filler plate? if so i am interested

 

When I used to have my Avalanche I left the front plate off and got a ticket while parked on sidestreet. Tried to contest it but was told that dealer require to drill the holes and provide you everything you need. Then again this was back in 03; either the cop was lying to me or rules have changed.

 

Here are two of the relevant sections of the CVC. There may be other sections that are relevant as well.

http://www.dmv.ca.gov/pubs/vctop/d03/vc5200.htm

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

According to Section 5201, license plates have to be securely fastened so that they do not swing. Now, this language does not preclude zip ties. However, if you only use two at the top, that's probably not going to cut it as the plate may swing.

Now, the interesting thing is whether Section 5201 (or any other CVC section) can be interpreted to preclude someone from mounting his/her license plate upside down (maybe?) or inside out (probably not.)