D.  There's still not quite enough room.  You have to cut a bit more of the shelf.  This is the passenger's side, the driver side is similar.

This is the passenger's side.

F. If the car has antilock brakes you will need to relocate the ABS sensor wiring harnesses. Jack up the rear of the car and support with sturdy jack stands. Remove the wheels and the plastic inner splash panels. The harnesses run from the sensors, mounted next to the brake rotors, up through rubber bulkhead plugs in the areas just to either side of the fuel tank. Trace the harnesses forward to the connectors just behind the seats, on either side of the area just uncovered by removal of the fuel tank cover / package shelf. Unplug the connectors, untangle the harnesses from the wire holders and other wiring, push the bulkhead plugs through and pull the wires through into the wheel wells. After the roll bar is bolted in, drill a 3/4" hole just far enough to the front or rear of the foot plate to clear, reroute the wiring and reinstall the bulkhead plugs.

G. This step is not required if you are installing an Ace.

The wiring to the fuel pump and gas gauge sending unit can get in the way.  The cover is held on by Phillips head screws and the harnesses un-clip.  The harnesses can then be pulled out through the rubber grommet and folded forward.  

There is also a wiring harness that runs across the car from one side to the other (not in the picture).  Unclip this and lift it forward too.  The bar will eventually fit in this area, and you don't want to pinch or cut anything by mistake.

6.  Trial Fit The Bar.  

Get some help, and be careful.  The passenger's side bar goes behind the battery cable.  Route the wiring harnesses, trunk and fuel door cables under the bar between the flat strips on the bottom. The large harness will eventually be connected over the top of the bar.

The horizontal mounting plates half way up the bar should fit over the top of the seat belt tower and align with the hole just inboard of the threaded seatbelt holes.

Position the spacer "C"  under the horizontal mounting plate.

Place the trim cap mounting washer "B" on the long bolt "A" and feed them through the mounting plate, the spacer and the hole in the seatbelt tower.

Position the flanged nut on the underside of the seatbelt tower and lightly tighten.  You'll want it firm enough to confirm the fit, but you don't want to torque it down yet.