simple one really...

are the holes in reg plates of a set distance apart and is it normal to buy them predrilled?

...and if you have to drill them yourself - whats a foolproof method to do this without damaging the rest of the plate?

 

Cover the plate in masking tape where you want to drill the holes. Make a small mark with a bradawl or something pointy to start you off, but don't overdo it, or the plastic will crack. Then drill CAREFULLY. Worked for me.

T

 

Put the old number plate over you new plate, gently drill onto the new plate using your old plate as a template for the correct hole position, stop drilling when your new plate has a drill mark on it.
move the old plate out of the way, put your new plate onto a piece of wood and drill straight through your new plate into the wood.
failure to have wood behind the plate whilst drilling will result in the backing tearing.. hope this helps

 

Make sure your old plates have been drilled correctly first

IE the holes are in the right place