Hi Will, not sure how much too big your rego plate is, but I cut about 15mm off each end of my plate to make it fit inside there perfect.
I used a dremel to make the cuts, and if you didn't know it was cut, you wouldn't see it.
I didn't cut into any of the numbers, so still legal.
PK
That's why i always come to this site, to "consult the oracle" hehehe! It's better this way, i'll try that. i found out that there's some room for fingers where the license plate lights are, so no big deal. Thank you