So here is the Night time footage with IR illuminator in my car, as you can see there is plenty of light but my illuminator just dont spread it enough inside the cabin.
So you will want a 5 - 7 watt IR illuminator with a wide beam angle, i would say 90 degrees or more should suffice for this job.
Colors are also fishy here , i am wearing a dark brown Jacket ( same as video above ) and a black and blue striped shirt ( same as above )
Bit other than that you do get a good face capture of me, and if the spread of light was better then also of anyone else that might be in the car.
I was going to run a test with just the bare IR emitter on its heat-sink without the glass in front of it, but then for some strange reason the fuse in the cigarette plug adapter blew on me
Anyway you can make a okay DIY kit but with blow out colors, but face captures should be good enough for a court case i would say.
Or you could buy a dashcam like the above mentioned Trancend and then add the IR illuminator to make sure you have enought light inside the car.
Hope this is something the would be Uber drivers of the world can use in their quest for personal securety and payback id they get some creep inside their car.