You'd need to fit this with a red bulb in place of the standard clear one. However, the MOT station might not think it is bright enough for a fog light depending on how strict they are. I remember we had this problem a while ago on an old FTO and solved it by fitting a dual filament rear light/brake red bulb there with it wired so both filaments came on together when the fog light was switched on.
That said, you cant do that on the 350z because the bulb is a large wedge bulb. You can buy red large wedge (I think they are called W21W's) bulbs but they are not that common. We used to do them from a company called Eurolite from America, but they have now gone out of business so I am not sure where you'd get a suitable bulb from.
I hope this helps
Louise