Pioneer GM-2000A Owner's Manual page 10

Inside the trunk
(Drill a hole into the Passenger
compartment
and pass the leads through it.)
10
Screw
(5 x 6 mm)
Bracket
Fig. 1
Tapping screw 4
(5 x 16 mm)
Y
Bracket
Drill 3 mm
diameter holes.
Fig. 2