I looked everywhere for the bolts for this thing, no one carrys the 1.25 pitch bolts. I finally got put in touch with Hilco and they had everything i needed in stock. i got a set of 10.9 grade six bolts, washers, and lock washers for a bit over $6. The staff was very helpful and even pulled all the parts for me through thier maze of a store. they even have cool anodized stuff.
http://www.hillcofasteners.com/
I put the four visible bolts in because i bought these ten minutes before i had to leave for a trip. i only put the four visible bolts in because i only needed to carry a bike rack. Do i have to pull the whole back bumper off to get the last two bolts in?