I relocated my plate just like you did. Made a nice aluminum bracket mounted to the underside of the bumper and a smaller bracket at the bottom to keep the plate solid. I just used two small circles of vinyl to cover the holes though. Can't be seen from more than 10 feet away. It'll look even better when I get my black and yellow 60's legacy plates (if the DMV gets the minimum 7500 orders. They're up to around 5300 so far!)
