From what I can see, illegal modifications are:
Pod filter + FMIC combo, aftermarket ECU, boost controller, catch can if it vents to atmosphere.
I'll assume the Philips headlight kit complies to ADR standards so that will pass.
The boost guage might be a problem if it's mounted on the A-pillar, so will the steering wheel if any part of it is highly reflective (ie. chrome) and distracts your vision (ie. glare). Also make sure because you don't have the stock gear stick knob, that you have a sticker to indicate your gear patterns.
Apart from checking the basics such as lights, wipers, etc, they will usually check your suspension and steering bushes under the car as well, so make sure steering boots or whatever aren't cracked and so forth. They will also check for exhaust leaks and if your engine and gearbox mounts are still in good condition.
Someone else might have more information for you.