I did what Chris suggests here with my 71. I did run the belt through the headrest, which keeps it positioned nicely. This retractor arrangement is a bit cumbersome and requires some getting used to, but seems to be a good solution. Plus, no hanging belt in a pillars-less coupe.Your Euro coupe had the fixed shoulder belt mounted behind rear seat armrest with a fixed or possibly retractable lap belt I assume. The 74 had a horizontal retractor behind the rear seat but you would need to modify or swap out the rear armrests and fabricate a mount. Sometime in 72 a fixture was added to the roof in front of the grab handle for the fixed shoulder belt. At this point any mod could be a bit challenging. Easiest is to mount the retractor on the rocker where the fixed lap mount is and use a belt long enough attach to rear seat area after it crosses your lap and shoulder and find something to hold it to the headrest post I would think. I believe Al is still around but he would need to know how long your belts would be.