I have not found a replacement cover to hide, but there are plenty of inserts to choose from
http://www.amazon.com/Genuine-Chevrolet-Bowtie-Brushed-Aluminum/dp/B0002RNQCK
http://www.thefind.com/cars/info-hitch-cover-chevy-bow-tie
http://www.thefind.com/cars/info-chevy-bow-tie-hitch
http://www.amazon.com/Genuine-Chevrolet-Bowtie-Brushed-Aluminum/dp/B0002RNQCK
http://www.thefind.com/cars/info-hitch-cover-chevy-bow-tie
http://www.thefind.com/cars/info-chevy-bow-tie-hitch