Good looking chop

certainly leaves Matts for dead (but thats another story

)
You wont be able to cut the glass down for the rear 1/4 cause its toughened and will shatter

as soon as you try

The perspex is easy though.
Use cardboard to make a pattern. Hold it over the outside of the hole (use tape or a helper

) Draw round the hole from the inside, then measure how much you need to add to fit to the edge of the body. You want to leave about 5mm gap between the edge of the perspex and the edge of the body. You can then flatten the cardboard out to get the shape to cut the perspex
Once you've got some perspex cut to size just heat it up along the bend line with a heatgun. The perspex gets real soft and you can pretty much bend it to whatever shape you want. you might want to practice with some offcuts so you know what it goes like, but its pretty straight forward.
Good luck
