thank you ! as the second row buckets i'm using have detachable head rests [with the attaching tubes like your seat[s] have], i will use those as you did for the mount attachment point. i have to cut into the lower seat pan to get the seat to fit the chassis kickup, then i can properly locate the cross bar so the shoulder belts are in the correct height. i also plan to make a shoulder belt guide that will locate off of the head rest posts to keep the belts properly aligned. thanks again for suggesting the use of the head rest mounting tubes for the location of the back brace attaching point !