I wouldn't worry about it. Hell, I have an FR-S with no front plate, so I
don't worry about it.
The thing about the front plate is that there is absolutely zero repercussion for repeatedly failing to obey the law. In other words, all you have to do is pay $15 now and then, and you never have to run a front plate ever again. That's pretty fair IMO---on the other hand, the "fee" for being able to drive as fast as you want all the time (aka speeding tickets and insurance) can get pricey!
To reiterate, just go without a plate. If you ever get pulled over, just accept the ticket. Mount the plate somehow (try a free method, like zip ties or something), meet an officer, go to the courthouse, and pay your 15 bucks. OP, if you're in SF, just head down to the station on Bryant and you can get a cop to sign off right in front of the courthouse.
In 10 years and 14 cars in this great state, I've gotten exactly ONE ticket for no front plate. I got it signed off, paid my fine at the courthouse, and then immediately took the plate back off
