enclosure top [lid] which is 1.5" in height. An aftermarket flat plate CNC cut from 1/4" PVC lid, replaces it freeing up 1.25" needed to mount the 6.5" beneath the speaker grill and hatch trim pieces. The plate has a 5.0" cut out. Ebay sells them for $18/ pair as 1990-1996 300ZX (Bose Model) 6 1/2" 6.5" Rear Speaker Adapters – SAK044_55