I have a sundowner front and rear for my Breakout and no grab strap or hardware.

 

Is the strap different (longer) from the stock one? If the stock one would work for you, I'll send you mine since I don't need it. It mounts to the factory seat post so there isn't any additional mounting hardware.

 

it's longer

 

Once the handles are off, check several body shops. The oval rubber knockout plugs are usually all over the place.