Yeah i would go for the dedicated solution too, and live with the colors on clothe being a bit off in daylight with that camera.
And then i would go for a good IR light source as the 4 LEDs often on such cameras are too little in my opinion.
If you want me to i can experiment a little with a camera of mine, but i dont think i have any wide angle lenses with no IR filter on them.
But i do have a massive IR light far overkilling what i would look for in such a setup ( 7 watt IR LED )
But it would be easy for me to put another lens on a little camera and throw that IR light source on my dashbord to see that kind of performance that will give in the dark Danish winter nights.
The Vantrue N2 dont appear to have IR, most cameras that have that will have 4 LEDs around the lens, and the footage off the vantrue N2 rear camera also appear to be color true and if the lens dident have a IR cut filter then colors would be off.
Off course there is such things as active IR filters like seen in CCTV cameras, but i dont think the Vantrue camera have that as there is no IR leds on it.
Transcend Drive Pro 520 have IR LEDS around its cabin lens, but they are weak and not good for people in the back of the car.
Just made this video with a camera on the middle of my dashbord, but this is daytime just to illustrate what kind of coverage you get in the cabin of a little car like mine .