The tray is used on the newer style Bonnevilles that have the ECU in the Air Cleaner box.
Your bonneville may not need the ECU tray if your ECU is not in the Air Box. As for the harness, you can use your stock harness with this unit now.

Yeah man, what rat said, its only in the airbox on ...what '95 and aboves? Ya dont have to worry bout it, but that hondas intake is lookin pretty nice to me right now......80 bucks

So I would need the separate box for my car??? I bet you could get the IAT sensor hole by the TB, and then just make a heat shield for it, that would save you alot of $$$.

civic intake tube at autozone for $39.99

Remember you get what you pay for! That filter is not a K&N like mine is either btw! Plus you'll still need to modify it for the Pontiac IAT Sensor too.

Yea it defintly takes some modification. I made my own, but that was before all of these new Bonneville companies opened up. You can buy the civic intake for $40, but then you would have to get a K&N air filter for it which is like $80 for the best [X-tream flow] and you would still have to modify it for the IAT sensor,and you would need to get the IAT harness extender [$25?]. Sure you can make your own, but the intake you can buy from one of the stores makes it a lot easier to install.

Will I need the PCM box for my '97?

Open your Air Cleaner, If there is an ECU in there (Bottom of box, big silver thing) then yes, you will need it.

On my car all I had to do was move my IAT sensor a little bit, there was plenty of slack in the line, and if not I cant imagine anyone would actually by a harness extender for $25 when you can just splice the wires.

A good filter that is K&N like is the Ractive, good reputable company.

Oh and about the IAT mounting... that wouldnt be hard with the proper drill bit. Plus if you were worried about a leak there you can simply reinforce it with clear silicone, or whatever color ya want really.

Remember some people are not mechanically inclined as we are!