Underdog, some will report cracks, others will report using special washers, spacers between the trunk lid outer and inner covers, etc., but the bottom line seems to be that, which ever rack you install (I have the Kury), only a very small amount of weight can be placed on the rack. I pack my Kury rack bag with rain gear and other outerwear, and that's it.
Good luck with your decision.
GWG