Not real sure on the glass question, but go to www.Thule.com
they make a number of bike racks. Many mount to the trunk and are removable. I have one of these I used on my '91 RX7 Convertable (before I traded it on the new GT) that adjusts and will fit my GT.
2008 Bullitt, #0546, Black
2005 GT Coupe, Performance White