So, it was figured out how to switch off the airbag light. Just take the orange wire from the instruments to ground. No resistors needed

Some people have passed IVA with the headlights, others have not. Rotating the lens may help, but it appears the discretion of the IVA tester is a factor as to whether these pass or not.

Car Builder Solutions sell the same lights but advise they are not IVA compliant and were originally designed for a motorbike

Two approaches have been taken for the fogs lights as the front are not compulsory. Some people have fitted the front fogs for IVA as the stalk has a switch for front and rear fogs. Other whose donor had front fog lights have bought (from eBay) a stalk from a model which does not have front fog lights. A demo of this type of stalk is shown below, the control of when the fog lights are/can be turned on/off is controlled by a manual mechanism in the stalk

The MX5 NC has a hyper flash feature which runs the indicators in a very fast pattern to indicate if a bulb is out. Replacing all the turn signals with LEDs triggers the hyper flash as the current that is drawn is significantly reduced. The IVA manual requires the turn signals to flash between 60 and 120 times per minute, which the hyper flash mode exceeds. There are a few options to overcome this, including resistors or using incandescent bulbs. However, resistors will run extremely hot and need to be well ventilated, and incandescent bulbs are often impractical. The most popular option is to cut one of the pins on the flasher module chip to disable the hyper flash.

Open the flasher module by pressing in the two tabs on each side and sliding out the circuit board. On the donor car, this was located above the pedals in the drivers footwell.

On the flip side to the capacitors and relays, you will locate this chip. Cut pin 8 (circled) so it is no longer attached. The easiest way is with some small cutters and snip the pin at the top and bottom.

A close up of the chip with the cut pin:

Doing this reduces the flash pattern to about 120 flashes per minute, so is right on the limit for IVA, and looks something like this:

If you are wanting a more OEM style flash pattern without using resistors and are confident with electronics & soldering, you can also change the capacitor for a 6.8uF 50v capacitor. This slows down the flash speed to roughly 85 flashes per minute and needs to be done as well as the chip modification. To do this, locate the capacitor labelled C1, and swap this with a 6.8uF capacitor. This example uses one rated to 50v but anything 35v or above will be fine, as it is generally good practice to use one rated to at least double the voltage. Also ensure the polarity is correct, + to + and – to -, if it is a polarized capacitor. For reference the OEM capacitor is 4.7uF 50v.

This will then reduce the flash pattern further, to look like this, approximately 85 flashes per minute: