You can get these from craigsplates.com. They do a slightly smaller than legal front show plate that is 410mm x 90mm that fits perfectly on the front bumper. It doesn't meet the legal requirements as the character height is around 5mm shorter than required. It does look good for a show plate though.

Thanks cyborg7, I just cut a standard one down, I clamped the plate between two pieces of wood and cut along with a hacksaw, I then filed it smooth.