i did mine with a jigsaw from inside the boot(under the shelf). I used the existing holes as one side, and cut out the other. They have been in 3 years and the cops(who pull me over regularly) have never said a thing. Could b different laws for different states? Anyway i broke quite a few jigsaw blades, but found that instead of pissing around, if you just cut hard and fast, it was easier. Providing u can follow ur cut-out line. I used 12mm mdf and made a new parcel shelf( instead of that dodgy thing that is factory) and bolted the speakers thru that and into the metal. They sit flush on the wood and look good. They go bloody hard too! (They are JBL GT series 6x9's)
White ED falcon, 2.5" redline zorst, pacemakers, 1 muffler, hi-flow cat, XH snorkel and K&N filter, 17" wheels, clear side and front indicators, king springs (low).