The HID I put in the motorbike passed 3 MOTs and a couple of roadside police inspections- the verdict was basically “totally illegal, but totally safe, so sod it” Probably helped that I went for a low colour temp, no blue in it unlike the boyracers.
But mostly, it was just well set up- it was actually a dual but only one of the headlights would aim well, the other was scattery and could have been glarey so I took it out and went back to halogen. The other one was good.
But anyway- I wouldn’t put one in a modern car, not like that anyway, my bike’s headlights were crap so it made more sense.