german plates on a UK car are both gay and illegal.

BSau145d requires the manufacturer name and postcode.

Even if you get a plate made with correct font, spacing, typeface etc, then it will still be illegal without the manufacturer on it.

The only reason is so that in theory the police can prosecute a plate manufacturer if they supply illegal plates for on road use. In reality no plate manufacturer would do that and would use the get out clause of stating "for off road use only".