I mounted mine this past weekend on my 03 SVT 3 door. The correct bolt sizes are as follows:
Front: 6 x 20 x 3/4 inch you will need 4 of these.
Rear: 8 x 20 x 3/4 inch you will need 2 of these.
For what its worth, BAT has spare / replacement parts available for the Kona racks as of today. Their website is:
Hope this helps some of you.